Updated link to RubyGems site
Update version numbers of Ruby and Rails
Modified "Allowing the update of fields" section

* Rails generate model Post ______ creates the
  attr_accessible line for you for any fields
  you specify. Changed the section to describe
  what this line in the model does.
Changed the Using Partials section to read a little better

* No need to give a simple example, as we have a
  partial that we create in the blog app
Added new line to make it more readable

* This shows the reader there is a method: and 
  data: parameters
Moved position of has_many
Updated with where functional/helper tests go
We should use post_path, not post_url
Reword Post model to note there are lines not shown
Revert "Updated with where functional/helper tests go"

This reverts commit c94cfdad6388dcdfaf4c10b9e8cee46baf2a7901.

* This is the new 4.0 (master) directory structure
Update guides/source/active_record_validations_callbacks.md

In the expiration_date_cannot_be_in_the_past validation method, use `expiration_date.present?` instead of the double negative `!expiration_date.blank?`. Also join the comparisons with `&&` instead of `and`, which could cause unintended consequences.
Merge pull request #119 from c0/master

Clarification to ActiveRecord Validations Doc in 7.2 Custom Methods
Use File.join to better integrate fixture_path in fixture_file_upload.
Set fixed-width style where appropriate on Getting Started guide.
Unused variable warning removed
unshift html-scanner into $LOAD_PATH rather than append
Merge pull request #8336 from rashmi14yadav/warning_removed

Unused variable warning removed
Merge pull request #8337 from amatsuda/unshift_html_scanner

unshift html-scanner into $LOAD_PATH rather than append
Fix Strong Parameters docs.

It's only possible to inherit from ActiveRecord::Base and not include
it.
Merge pull request #8338 from ugisozols/master

Fix Strong Parameters docs [ci skip]