Be a bit less conservative with mysql in adapter
Refactor request tests, remove #with_set method
Fix issue with params in url_for

With a "params" argument, the following error is raised:

    undefined method `reject!` for "":String
Correct the use of params options when given to url_for

Merge url for tests and add changelog entry for #8233.
Merge branch 'url-for-params'

Fix error when using a non-hash query argument named "params" in `url_for`.

Before:

    url_for(params: "") # => undefined method `reject!' for "":String

After:

    url_for(params: "") # => http://www.example.com?params=`

Closes #8233
Better Error handling when parsing database.yaml

Provides a better error message incase the database.yaml
has some errors.
Merge pull request #8279 from gaurish/database_error

Improved Error handling when parsing database.yaml, Fixes #8143
bug in example '<%= form_for ...' should be '<% form_for ...'
remove previous commit
embed code example using backticks in caching guide
fix guide with field_with_error proc example
fixed a minor spelling error
Postgresql doesn't accepts limits on text columns.
Merge pull request #8276 from pwnall/pgsql_text_limits

Postgresql doesn't accepts limits on text columns
Initialize accessors to remove some warnings in Ruby 2.0
Merge pull request #8282 from arunagw/warning_removed_for_ruby2

Initialize accessors to remove some warnings in Ruby 2.0
Merge pull request #8280 from asanghi/fix_guide_field_with_error_proc

fix guide with field_with_error proc example
Remove return guard and use code convetions
Fix postgresql adapter to handle bc timestamps correctly
Refactoring, testing and documenting pg_connection.distinct