Merge pull request #392 from dcmaf/gh-pages

Small corrections/changes
Add note about js extensions in R.js build config
For #377 - merging new mobile section with fixes, linkifying URLs, correcting image paths
Merge branch 'gh-pages' of http://github.com/addyosmani/backbone-fundamentals into gh-pages

* 'gh-pages' of http://github.com/addyosmani/backbone-fundamentals:
  Fixes to the new Event Aggregator/Mediator sections
  More cleanup.
  Internals chapter: tweaked first paragraph of Events section.
  More minor updates to recently changed sections.
  Extensions: minor corrections, including removing redudantcy in Thorax Hello World section.
  Fundamentals: minor punctuation and typo fixes
Merge pull request #393 from jackfranklin/gh-pages

RequireJS Section Tweaking
For #342 - adding note about Router.navigate
Merge branch 'gh-pages' of http://github.com/addyosmani/backbone-fundamentals into gh-pages

* 'gh-pages' of http://github.com/addyosmani/backbone-fundamentals:
  Add note about js extensions in R.js build config
For #342 - adding a note about the backbone validation plugin
For #342 - trying to make sense of the validation section in common problems
For #342 - adds a backbone diagram as requested
Tweaked Backbone.Validation example to make example parallel to the Backbone.validateAll example.
Tightened sentence and fixed punctuation in R.js build config note.
Reworded navigation section with trigger:true option. Also changed option name from 'navigate' to 'trigger' to match the Backbone documentation (and source code).