Fixing the broken readme links [skip ci]

The README Links for activerecord & actionapack are broken on page http://api.rubyonrails.org/, throwing 404.  Since Links starting with link: refer to local files .  Providing the absolute path.
Some performance benchmarking for take vs limit

Also added a dummy progress bar during insert of records so it shows something is happening.
Performance report
          Model.take     6198.9 (±13.4%) i/s -     121743 in  20.042671s
         Model.take!     6173.6 (±13.6%) i/s -     121242 in  20.057006s
Model.all limit(100)      107.8 (±15.8%) i/s -       2106 in  20.022316s
 Model.all take(100)      105.2 (±15.2%) i/s -       2061 in  20.062509s
Conflict resolve
Refactored strong paramters usage and updated Gemfile.lock with Rails 4
Refactored strong paramters usage and updated Gemfile.lock with Rails 4
Fixing broken link for upgrading Rails from 3.2 to 4.0 [skip ci]
Refactoring: Around validation syntaxes in the models

also lambda syntax at couple of instances
Refactoring: Test models with the syntax change for validates

also change in lambda syntaxes at some instance
Refactoring of Test models with the syntax change for validates
also change in lambda syntaxes at some instance
re
re
rc
Merge remote-tracking branch 'origin/upstream'
Merge remote-tracking branch 'upstream/ank'
Merge remote-tracking branch 'upstream/ar-refac'