ilastik.cmake: On Mac OS, rename the drtile.dylib library to drtile.so, since Python seems to insist on that name.
ilastik-gui: Don't include chatty.  It didn't belong here in the first place, and doesn't build on Mac.
lemon.cmake:
- Explicitly disable GLPK support
- Added a comment about (lack of) clang support for this package.