Renamed the SanitizerTest class to SanitersTest, to remove the conflict with the old SanitizerTest for html-scanner.

Removed the contains_bad_protocols? method as well as the tests for it. Loofah already deals with this.

Implemented ActionView: FullSanitizer, LinkSanitizer and WhiteListSanitizer in sanitizers.rb.
Deprecated protocol_separator and bad_tags.
Added new tests in sanitizers_test.rb and reimplemented assert_dom_equal with Loofah.

Add test cases for #in? and #presence_in

Remove deprecation warning

Ensure `column_types` returns a type object, and not a column

Remove YAML serialization workaround for columns

We are no longer including column objects in YAML serialization, thanks
to https://github.com/rails/rails/pull/15621

Follow up to #15636.

/cc @hundredwatt

Fix Apache Directives [ci skip]

Directives need to be placed on their own lines in order to work. Tested on: `Server version: Apache/2.2.22 (Ubuntu); Server built:   Mar 19 2014 21:11:15`

add missing changelog entry. refer [#16db90d1] [ci skip]

No need to decorate columns twice

[ci skip] Fix doc for javascript_helper

We never want result types to override column types, and
`decorate_columns` can only affect column types. No need to go through
the decoration multiple times, we can just exclude the column types from
the result types instead.

Correct Bundler link [ci skip]

[ci skip] Refine Action Mailer guide.

* Wrap 80 words if possible.
* Make attachment hash options more readable. (L239-L243)

  Before:

  ![screenshot 2014-06-11 02 59 54](https://cloud.githubusercontent.com/assets/1000669/3235432/a91d0464-f0d2-11e3-9e4a-6af2b2a83f1a.png)

   After:

  ![screenshot 2014-06-11 02 59 36](https://cloud.githubusercontent.com/assets/1000669/3235428/a47b28dc-f0d2-11e3-806c-cfaedd3f15df.png)

* L619 Wrap "location" in code: `"location"`.
* L628 Use actual section name.
* L697 Remove unnecessary `./` when refer to other guide.