Merge pull request #10275 from buddhamagnet/master

Increase readability of ternary statement in build method
fix typos
Make guide description more concise
Merge pull request #10280 from vipulnsward/fix_typos_temp

fix typos [ci skip]
Removing tests for deprecated options in active support. The
+use_full_path+ option was removed in 3b3790a4 and passing the template
handler to render was deprecated in 43d27e91.
Merge pull request #10283 from wangjohn/remove_tests_for_deprecated_options

Removing tests for deprecated options in active support.
Added tests for if condition in Active Model callbacks
Merge pull request #10284 from neerajdotname/missing-active-model-tests

Added tests for if condition in Active Model callbacks
fix wrong test description and failure message
Merge pull request #10286 from neerajdotname/fix-wrong-test-name-and-failure-message

fix wrong test description and failure message
Refer to 37signals blog post for alternative

According to the rationale at https://github.com/rails/rails/pull/7833#issuecomment-9141908, we should recommend new users to follow DHH's approach outlined at http://37signals.com/svn/posts/3113-how-key-based-cache-expiration-works.

This is the first step, and perhaps in the future we can write some specific recommendations out.
Updates list of assertions in testing guide
fixes typo in testing guide
fix README links in the main README.md
Merge pull request #10289 from maratvmk/readme

fix README links in the main README.md
extract path into variable
Merge pull request #10290 from buddhamagnet/master

Extract path into variable
Update counter cache when pushing into association

This commit fixes a regression bug in which counter_cache columns
were not being updated correctly when newly created records were
being pushed into an assocation. EG:

    # this was fine
    @post.comment.create!

    # this was fine
    @comment = Comment.first
    @post.comments << @comment

    # this would not update counters
    @post.comments << Comment.create!
extract array to a constant
Merge pull request #10293 from vipulnsward/dont_mutate_callback

extract array to a constant