OSX build patches
Fixed the Tab-key implementation for all warp classes. Changed the solution for the osx compatibility as suggested by Gabor Papp to one using const references, because I think it is cleaner. I hope this works on osx, too.
Changed the type of mSelected to unsigned and fixed the comparison, as suggested by Gabor Papp.
Changed all size_t's to unsigned integers.
Removed additional unsigned warnings.