Added success and error information to -[GTIndex clear:]. closes #361
Merge pull request #394 from pbendersky/master

Added success and error information to -[GTIndex clear:]
Removed libz from linked libraries to prevent a warning in Xcode 6 when compiling ObjectiveGit-ios (static libraries can't link to dynamic libraries).
Merge pull request #396 from pbendersky/master

Removed libz from linked libraries to prevent a warning in Xcode 6 when compiling ObjectiveGit-ios (static libraries can't link to dynamic libraries).
Merge branch 'master' into fetch