Added OCE_USE_BUNDLE_SOURCE flag as an alternative to OCE_USE_BUNDLE. Wh...

When OCE_USE_BUNDLE_SOURCE is enabled, set OCE_BUNDLE_ROOT_PATH to the path to an oce-win-bundle source directory. The oce-win-bundle projects (FTGL, freetype, gp2ps, and FreeImage) will be added to and compiled with the same CMake project as OCE. When using Visual Studio, this creates one solution file that contains OCE plus all the libraries of oce-win-bundle and sets appropriate inter-project dependencies.

Note that for this to work lines 5-10 in oce-win-bundle's CMakeLists.txt need to be changed from CMAKE_SOURCE_DIR to CMAKE_CURRENT_SOURCE_DIR. These changes have been posted to the oce-win-bundle site as an issue but they have not yet been incorporated.

Holler if you run into any problems or have any suggestions for improvement.