Merge pull request #13 from khawkins/unstable

Latest SalesforceCommonUtils (fixes CocoaLumberjack clashes)
Removing RestKit from 3PP for upcoming release
Merge pull request #14 from khawkins/remove_restkit

Removing RestKit from 3PP for upcoming release
Merge pull request #15 from khawkins/master

Mobile SDK 2.1: Unstable to master merge