MOBSDK-548:  AlfrescoErrors.m implementation could be cleaner
MOBSDK-551: Drop forward method declarations for private methods
Merge pull request #150 from msaeedi/master

MOBSDK-548, MOBSDK-551
MOBSDK-554: Updating document contents via iOS SDK returns out-of-date document modification date, MOBSDK-518: Updating document contents via iOS SDK for file created via SDK does not update the version number
Merge branch 'master' of https://github.com/Alfresco/alfresco-ios-sdk into topic-MOBSDK-544-518