README updates
Apex-rest addition
Rewording the doc
Add note about auth delegate
Merge pull request #463 from bhariharan/unstable

README updates
Merge pull request #462 from khawkins/unstable

2.0 to 2.1 upgrade instructions
Updating 2.1 submodules, version
Merge pull request #464 from khawkins/master

Mobile SDK 2.1: Unstable to master merge