Mobile SDK 2.3.1 patch
Merge pull request #769 from khawkins/master

Mobile SDK 2.3.1 patch
Merge remote-tracking branch 'origin/master' into unstable_merge

Conflicts:
	libs/SalesforceSDKCore/SalesforceSDKCore/Classes/Common/SalesforceSDKConstants.h
Merge pull request #770 from khawkins/unstable_merge

Mobile SDK: Merging master to unstable