Issue: SPR-11297
(cherry picked from commit fc361844)

Restoring consistency with AnnotationConfigApplicationContext.

Issue: SPR-10852

Before this change there were numerous javadoc warnings being reported
while building Spring framework API.

This commit resolves most of the javadoc warnings, reducing the total
number from 265 to 103.

Issue: SPR-9113

This renaming more intuitively expresses the relationship between
subprojects and the JAR artifacts they produce.

Tracking history across these renames is possible, but it requires
use of the --follow flag to `git log`, for example

    $ git log spring-aop/src/main/java/org/springframework/aop/Advisor.java

will show history up until the renaming event, where

    $ git log --follow spring-aop/src/main/java/org/springframework/aop/Advisor.java

will show history for all changes to the file, before and after the
renaming.

See http://chrisbeams.com/git-diff-across-renamed-directories

Per review with Juergen in light of SPR-8413, which will revisit the
overall structure of ACAC and ACWAC.

Issue: SPR-8365, SPR-8413

WebApplicationInitializer provides a programmatic alternative to the
traditional WEB-INF/web.xml servlet container deployment descriptor
for Servlet API 3.0+ environments.

This is done by building atop the new ServletContainerInitializer
support in Servlet 3.0. See SpringServletContainerInitializer for
complete details. And see WebApplicationInitializer Javadoc for
typical usage examples.

Issue: SPR-7672

AnnotationConfigApplicationContext and
AnnotationConfigWebApplicationContext both expose #register and #scan
methods as of the completion of SPR-8320. This change introduces a new
interface that declares each of these methods and refactors ACAC and
ACWAC to implement it.

Beyond information value, this is useful for implementors of the
ApplicationContextInitializer interface, in that users may create an ACI
that works consistently across ACAC and ACWAC for standalone (e.g.
testing, batch) or web (e.g. production) use.

Issue: SPR-8365,SPR-8320

Primarily for use in conjunction with ApplicationContextInitializer,
these new #scan and #register methods mirror those in
AnnotationConfigApplicationContext. #setConfigLocation
and #setConfigLocations methods remain for compatibility with
ContextLoader-style initialization, but have been locally overridden
and documented clearly.

AnnotationConfigWebApplicationContext#loadBeanDefinitions Javadoc has
also been updated to explain the processing logic for each of these
potential inputs.

Issue: SPR-8320

Decomposed Environment interface into PropertySources, PropertyResolver
objects

    Environment interface and implementations are still present, but
    simpler.

    PropertySources container aggregates PropertySource objects;
    PropertyResolver provides search, conversion, placeholder
    replacement. Single implementation for now is
    PropertySourcesPlaceholderResolver

Renamed EnvironmentAwarePropertyPlaceholderConfigurer to
PropertySourcesPlaceholderConfigurer

    <context:property-placeholder/> now registers PSPC by default, else
    PPC if systemPropertiesMode* settings are involved

Refined configuration and behavior of default profiles

    See Environment interface Javadoc for details

Added Portlet implementations of relevant interfaces:

    * DefaultPortletEnvironment
    * PortletConfigPropertySource, PortletContextPropertySource
    * Integrated each appropriately throughout Portlet app contexts

Added protected 'createEnvironment()' method to AbstractApplicationContext

    Subclasses can override at will to supply a custom Environment
    implementation.  In practice throughout the framework, this is how
    Web- and Portlet-related ApplicationContexts override use of the
    DefaultEnvironment and swap in DefaultWebEnvironment or
    DefaultPortletEnvironment as appropriate.

Introduced "stub-and-replace" behavior for Servlet- and Portlet-based
PropertySource implementations

    Allows for early registration and ordering of the stub, then
    replacement with actual backing object at refresh() time.

    Added AbstractApplicationContext.initPropertySources() method to
    support stub-and-replace behavior. Called from within existing
    prepareRefresh() method so as to avoid impact with
    ApplicationContext implementations that copy and modify AAC's
    refresh() method (e.g.: Spring DM).

    Added methods to WebApplicationContextUtils and
    PortletApplicationContextUtils to support stub-and-replace behavior

Added comprehensive Javadoc for all new or modified types and members

Added XSD documentation for all new or modified elements and attributes

    Including nested <beans>, <beans profile="..."/>, and changes for
    certain attributes type from xsd:IDREF to xsd:string

Improved fix for detecting non-file based Resources in
PropertiesLoaderSupport (SPR-7547, SPR-7552)

    Technically unrelated to environment work, but grouped in with
    this changeset for convenience.

Deprecated (removed) context:property-placeholder
'system-properties-mode' attribute from spring-context-3.1.xsd

    Functionality is preserved for those using schemas up to and including
    spring-context-3.0.  For 3.1, system-properties-mode is no longer
    supported as it conflicts with the idea of managing a set of property
    sources within the context's Environment object. See Javadoc in
    PropertyPlaceholderConfigurer, AbstractPropertyPlaceholderConfigurer
    and PropertySourcesPlaceholderConfigurer for details.

Introduced CollectionUtils.toArray(Enumeration<E>, A[])

Work items remaining for 3.1 M2:

    Consider repackaging PropertySource* types; eliminate internal use
    of SystemPropertyUtils and deprecate

    Further work on composition of Environment interface; consider
    repurposing existing PlaceholderResolver interface to obviate need
    for resolve[Required]Placeholder() methods currently in Environment.

    Ensure configurability of placeholder prefix, suffix, and value
    separator when working against an AbstractPropertyResolver

    Add JNDI-based Environment / PropertySource implementatinos

    Consider support for @Profile at the @Bean level

    Provide consistent logging for the entire property resolution
    lifecycle; consider issuing all such messages against a dedicated
    logger with a single category.

    Add reference documentation to cover the featureset.

Branch in question is 'env' branch from git://git.springsource.org/sandbox/cbeams.git; merged into
git-svn repository with:

    git merge -s recursive -Xtheirs --no-commit env

No merge conflicts, but did need to

    git rm spring-build

prior to committing.

With this change, Spring 3.1.0 development is now happening on SVN
trunk. Further commits to the 3.0.x line will happen in an as-yet
uncreated SVN branch.  3.1.0 snapshots will be available
per the usual nightly CI build from trunk.

Updated documentation to point out that AnnotationConfigWebApplicationContext can accept both fully-qualified class names as well as base packages to the contextConfigLocation init-param.

reworked ConfigurationClass(Web)ApplicationContext into AnnotationConfig(Web)ApplicationContext; revised BeansException signatures