Cleanup application.css

XSS attacks.  Thanks Sascha Depold for the report.

Use lazy load hooks to set parameter wrapping configuration. This means that it doesn't force Action Controller / Active Record to load, but it doesn't fail if they have already loaded. Thanks @josevalim for the hint.

Fix formatting of active_record_validations_callbacks.textile so guide will render properly at http://edgeguides.rubyonrails.org/active_record_validations_callbacks.html#displaying-validation-errors-in-the-view

Don't reference ActiveRecord::Base in initializers/wrap_parameters.rb. Use config.active_record instead. This yields about a 20% decrease in startup time because it means that the connection is not created immediately on startup. Of course, this is only useful if you are not going to immediately use the database after startup.

In 1efd8828, ConnectionAdapters was put under eager_autoload. Due to the requires in that file, this caused ConnectionSpecification to be loaded, which references ActiveRecord::Base, which means the database connection is established. We do not want to connect to the database when Active Record is loaded, only when ActiveRecord::Base is first referenced by the user.

This reverts commit 87152f26, reversing
changes made to 0d3615f0.

Remove unused require in activerecord/test/cases/attribute_methods_test.rb

Fix tzinfo require (it broke test_raises_when_an_invalid_timezone_is_defined_in_the_config in railties)

Don't refer to ActionController::Base in the wrap_parameters initializer - use config object instead. Cuts about 15% off the load time. (#734)

yield(:unspecified_block) actually returns true even if :unspecified_block never
exists. This means you can't use the form yield(:unspecified_block) or yield.

Grammar/syntax/style changes:
1. Changed all 'we' to 'you'
2. Corrected typos
3. Make consistent styline (e.g., dashes & double-dash usage)
4. Change use of future tense (will...) to present tense (easier to read).

Delegate expl