Cleaned up wording and tags.

Replaced <br /> with <br> for consistency; Added note about
singular/plural distinction (which was previously confusing to a Rails
noob); Rephrased explanation of how form is routed to controller, again
to reduce confusion; and added explanation to replace incorrect link.
[ci skip]
Merge pull request #11336 from ankit8898/performance-bm

Some performance benchmarking for take vs limit
Merge pull request #11324 from blahedo/master

Cleanup on getting_started tutorial
Merge pull request #11313 from gsamokovarov/url-encoded-params-test

Cleanup ul_encoded_params_parsing_test
Removed unused test for DateTime.local_offset

see discussion here #11274
Fix link_to with block and url_hash

Use link_to with block and url_hash, expect block as name.
But ignore block and use url_hash as name.
3-2-stable passes this test. 4-0-stable and master fail this.
Added an `enforce_utf8` hash option for `form_tag` method

Control to output a hidden input tag with name `utf8` without monkey
patching

Before:

    form_tag
    # => '<form>..<input name="utf8" type="hidden" value="&#x2713;" />..</form>'

After:

    form_tag
    # => '<form>..<input name="utf8" type="hidden" value="&#x2713;" />..</form>'

    form_tag({}, { :enforce_utf8 => false })
    # => '<form>....</form>'
Merge pull request #11274 from arunagw/deprecation-removed-build-fixed

Deprecation removed build fixed
Refactored strong paramters usage and updated Gemfile.lock with Rails 4
Merge pull request #11317 from ma2gedev/enforcer_tag_option

Added an `enforce_utf8` hash option for `form_tag` method
Merge pull request #11347 from ankit8898/refactoring-sp

Refactored strong parameters usage and updated Gemfile.lock with Rails 4
Include block in a argument shift
Fix "Stack Level Too Deep" error when rendering recursive partials

When rendering recursive partial Action View is trying to generate the
view digest infinitly causing a stack level error.

Fixes #11340
Merge pull request #11348 from sanemat/fix/link-to-block

Fix actionview link_to with block and url_hash
Add CHANGELOG entry for #11348
Use helper method to get ENV['CONTENT_LENGTH']
Use Request#raw_post instead Request#body

In order to get raw_post to be not empty after
ParamsParser#parse_formatted_parameters,
added rewinding of body stream input on parsing json params.

Closes #11345
cache.exists? should return true/false
Explicitly test for true and false.
Creating a class for carrying out rails commands.

This class encapsulates a lot of logic that wasn't very object oriented.
Helper methods have been created to try to make things more logical and
easy to read.