Minor updates for latest compilers.

git-svn-id: http://gdata-objectivec-client.googlecode.com/svn/trunk@739 f334b912-182a-0410-b59a-f50d4d03ee1a
Update for Xcode 5.1

git-svn-id: http://gdata-objectivec-client.googlecode.com/svn/trunk@740 f334b912-182a-0410-b59a-f50d4d03ee1a
Update for newer compilers.

git-svn-id: http://gdata-objectivec-client.googlecode.com/svn/trunk@741 f334b912-182a-0410-b59a-f50d4d03ee1a