delete gtest for merge


git-svn-id: http://protobuf.googlecode.com/svn/trunk@600 630680e5-0e50-0410-840e-4b1c322b438d
merge tags/2.6.0 into trunk


git-svn-id: http://protobuf.googlecode.com/svn/trunk@601 630680e5-0e50-0410-840e-4b1c322b438d
change back to gtest head


git-svn-id: http://protobuf.googlecode.com/svn/trunk@602 630680e5-0e50-0410-840e-4b1c322b438d
merge 2.6.0 to trunk


git-svn-id: http://protobuf.googlecode.com/svn/trunk@604 630680e5-0e50-0410-840e-4b1c322b438d