* implemented cuda binary caching (a 128-bit cityhash is computed from the preprocessed (!) opencl code (this way, any build options and include files changes will result in a different hash), which is then used for the filename of the to-be-cached generated/compiled ptx file; a cache file list from data/cache/ is generated at program start and cached binaries are loaded as needed; behavior can be managed via the cuda settings in config.xml)
 * added cuda.use_cache config setting (cuda.keep_binaries determines if binaries are cached, cuda.use_cache determines if these cached binaries are actually used)
 * added preliminary (but functional!) cuda profiling support (this will compile code with line information for both the ptx and the compiled cubin file, i.e. flags are passed to cicc and the jit compiler)
 * added (untested) cuda debugging support (optimization level is not properly configurable yet, so full optimization is still used)
 * temporary cuda compilation files are now also stored in data/cache/ (this is necessary for proper profiling support; no cleanup yet)
 * limited local memory size usage to 6k for now (now that I can actually profile oclrasters code, this is one of the first big issues I found; more changes to come)
 * removed (direct) zlib dependency (now that crc32 isn't used any more)