[Stephen Ausman + Fabrizio Regini]

Instead of deleting the skip_digest option flag, this changes the method to merely check the
key. This change is because of a discussion in this thread:

https://github.com/rails/rails/pull/8317

This commit also makes #fragment_name_with_digest private due to its
functionality being subsumed by #cache_fragment_name.

This add support for sending an explicit opt-out of the "Russian-doll"
cache digest feature on a case-by-case basis. This is useful when cache-
expiration needs to be performed manually and it would be otherwise
difficult to know the exact name of a digested cache key.

More information: https://github.com/rails/cache_digests/pull/16

Move the CacheHelper#fragment_name_with_digest to be public so custom fragment caching can benefit from it.

Add automatic template digests to all CacheHelper#cache calls (originally spiked in the cache_digests plugin) *DHH*

Fix fragment caching (squashed commits)

Contains following patches cherry-picked from @lhahne's 3-0-stable branch:

* Added tests for the output_buffer returned by CacheHelper (c476a6be)
The output_buffer returned by CacheHelper should be html_safe if the original buffer is html_safe.

* made sure that the possible new output_buffer created by CacheHelper is of the same type as the original (39a4f67b)

Adapt [823aa223] to make sure we perform cloning before manipulation only on `OutputBuffer`.

After the fragment rendering, `Builder` returns the `String` object instead of `ActionView::OutputBuffer`. Somehow the same procedure which was in [823aa223] does not play nice with the String, and result in the fragment got lost.

safebuffer.

  * The cache helper is now semantically "mark this region for caching"
  * As a result, <% x = cache do %> no longer works

  * The approach is to compile <% %> into a method call that checks whether
    the value returned from a block is a String. If it is, it concats to the buffer and
    prints a deprecation warning.
  * <%= %> uses exactly the same logic to compile the template, which first checks
    to see whether it's compiling a block.
  * This should have no impact on other uses of block in templates. For instance, in
    <% [1,2,3].each do |i| %><%= i %><% end %>, the call to each returns an Array,
    not a String, so the result is not concatenated
  * In two cases (#capture and #cache), a String can be returned that should *never*
    be concatenated. We have temporarily created a String subclass called NonConcattingString
    which behaves (and is serialized) identically to String, but is not concatenated
    by the code that handles deprecated <% %> block helpers. Once we remove support
    for <% %> block helpers, we can remove NonConcattingString.

Made ActionView::Base#first_render a little more private. And added _last_render to track the most recent render. Will fix #609 as a side effect. [#609 state:resolved]

This reverts commit 42d215a9.

Conflicts:

	actionpack/lib/action_view/inline_template.rb
	actionpack/lib/action_view/template.rb

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8981 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8791 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

Reapply the TemplateFinder first applied in [8669] then reverted in [8676]. Closes #10800 [lifofifo]


git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8683 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8676 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8669 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8630 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8619 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@8614 5ecf4fe2-1ee6-0310-87b1-e25e094e27de