[cmake] Check for libraries and create `ftoption.h'.

* builds/FindHarfBuzz.cmake: New file, taken from

  https://trac.webkit.org/browser/trunk/Source/cmake/FindHarfBuzz.cmake

* CMakeLists.Txt: Add path to local cmake modules.
Find dependencies for zlib, bzip2, libpng, and harfbuzz.
Create `ftoption.h' file.
Set up include and linker stuff for libraries.
3 files changed