Updated ModelSync.Local code
Unit tests for ModelSync.Local
Updated Model docs with ModelSync.Local usage
Updated App metadata with ModelSync.Local
Update App's unit testing HTML with ModelSync.Local
Update build.json with ModelSync.Local
Improving returned errors in local syncing.
Additional test case for errors such as QUOTA_EXCEEDED_ERR
Merge branch 'model-sync-local' of https://github.com/clarle/yui3 into model-sync-local
IE6 - 8 fix for ModelSync.Local

Fixes bug with the fallback cache when localStorage is unavailable.
Fixes IE6 - 8 bug inside of ModelSync.Local tests
Merge branch 'dev-3.x' of https://github.com/yui/yui3 into model-sync-local
Add changes based on @ezequiel's suggestions

* Switched to feature testing, rather than feature detection
* Various fixes to improve code clarity
Update to new `localStorage` mechanism

This new mechanism now stores data in the folllowing way:

Key   : 'users'
Value : [{id: 'users-1', name: 'clarle'}, {id: 'users-2}, name: 'ericf'}]

This guarantees the order of the values. A in-memory lookup table by `id` is
used to do lookups faster than iterating through the entire array.
Add suggestions from @ericf on ModelSync.Local

* Add try/catch to JSON.parse
* Add a few clarifying comments on `initializer`
* Using clearer conditional assignment style
Add assertions for load order in MS.Local tests
Build ModelSync.Local
Merge branch 'model-sync-local' into dev-3.x

Conflicts:
	build/loader-yui3/loader-yui3-coverage.js
	build/loader-yui3/loader-yui3-debug.js
	build/loader-yui3/loader-yui3-min.js
	build/loader-yui3/loader-yui3.js
	build/loader/loader-debug.js
	build/loader/loader-min.js
	build/loader/loader.js
	build/yui-nodejs/yui-nodejs-debug.js
	build/yui-nodejs/yui-nodejs-min.js
	build/yui-nodejs/yui-nodejs.js
	build/yui/yui-debug.js
	build/yui/yui-min.js
	build/yui/yui.js
	src/loader/js/yui3.js