Added link to x265 online documentation.
Improved VapourSynth detection code, so that 64-Bit version can be detected as well. Since we cannot load the 64-Bit DLL, we will no longer attempt to load the VSSCRIPT.DLL directly, but instead just run VSPIPE.EXE and read out the version number. This is going to fail, if the VSSCRIPT.DLL is missing on the system.