The URI template is now manually parsed vs using a regex to extract
URI variable names and to create a pattern for matching to actual URLs.
This provides more control to deal with nested curly braces.

Issue: SPR-13627

Issue: SPR-12750

This commit introduces support for "Path Segment URI Variable
expansion", see https://tools.ietf.org/html/rfc6570#section-3.2.6.
In practice, this means that URI template variables prefixed with a '/'
are treated like path segments and - as such - will encode any '/'
found. For example: {/foo} expanded with "bar/baz" with result in
"bar%2F".

Issue: SPR-12750

This reverts commit a57d4282 after the
realization of a weaknesses with the proposed approach.

For example if a path segment contains both a /-prefixed and a regular
URI variable, there is no way to split that into a sequence of path
and path segments. The solution will have to be on the side of
UriComponents at the time of encoding.

Issue: SPR-12750

Issue: SPR-10127

  find . -type f -name "*.java" -or -name "*.aj" | \
    xargs perl -p -i -e "s/[ \t]*$//g" {} \;

Issue: SPR-10127

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

SPR-5973: UriComponents no longer a Map, moved all static methods from UriComponents to builder, added expand method to UriComponents

SPR-5973: Using UriComponents in more places, replaced UriBuilder by UriComponentsBuilder, UriComponents is now immutable.