Remove commented railties boot_test.rb

Renaming the check_empty_arguments method to something more descriptive.

This reverts commit bb842e8d, reversing
changes made to 40c287c7.
This was causing issues in one of our apps we just upgraded.
ActionController::RoutingError: No route matches [GET]
"/images/favicon.ico"
favicon_link_tag now returns '/images/favicon.ico' and in 3.2 returned
'/favicon.ico'
Browsers by default look for favicon.ico in the root directory

Conflicts:
	actionpack/CHANGELOG.md
	actionpack/lib/action_view/helpers/asset_tag_helper.rb

unify AR changelog entries [ci skip]

also rename indexes when a table or column is renamed

When a table or a column is renamed related indexes kept their name. This will lead to confusing names. This patch renames related indexes when a column or a table is renamed. Only indexes with names generated by rails will be renamed. Indexes with custom names will not be renamed.

The function is now called has_arguments? so that it's easier to tell
that it's just checking to see if the args are blank or not.

deal with long index names and internal sqlite3 operations

Some adapter (SQLite3) need to perform renaming operations to support
the rails DDL. These rename prefixes operate with prefixes. When an
index name already uses up the full space provieded by
`index_name_length` these internal operations will fail. This patch
introduces `allowed_index_name_length` which respects the amount of
characters used for internal operations. It will always be <=
`index_name_length` and every adapter can define how many characters
need to be reserved.

Tests to make sure empty arguments in WhereChain raise errors

Fix ActiveRecord::ConnectionAdapters::ConnectionSpecification::ResolverTest

Reduced memory leak problem in transactions by lazily updating AR objects

move config.assets.precompile into config/application.rb

for query methods in a where_clause. Also, modified the CHANGELOG entry
because it had false information and added tests.

Reduced memory leak problem in transactions by lazily updating AR objects with new transaction state. If AR object has a callback, the callback will be performed immediately (non-lazily) so the transaction still has to keep records with callbacks.

fix rake db:migrate when used with ENV['DATABASE_URL']

make connection_url_to_hash a class method

This als prevents loading database.yml if it doesn't exist
but DATABASE_URL does

Remove XML Parser from ActionDispatch

If you want an ability to parse XML parameters, please install
`actionpack-xml_parser` gem.

descriptive error message when AR adapter was not found. Closes #7313