Clarify GTDiff options argument documentation
Clarify GTDiff options argument documentation

The diff initializers refer to their options arguments taking
"any of the above options", but both GTDiffOptions and
GTDiffFindOptions are defined above them and the diff
initializers really only accept GTDiffOptions.
tiennou/objective-git,alehed/objective-git,alehed/objective-git,dleehr/objective-git,phatblat/objective-git,phatblat/objective-git,libgit2/objective-git,blackpixel/objective-git,libgit2/objective-git,tiennou/objective-git,tiennou/objective-git,phatblat/objective-git,libgit2/objective-git,dleehr/objective-git,libgit2/objective-git,alehed/objective-git,blackpixel/objective-git,dleehr/objective-git,blackpixel/objective-git,blackpixel/objective-git,dleehr/objective-git