Improve compability with AviSynth+

port from BugMaster's patch for x264
Add requirements for some source filters
Rename avs4x264mod to avs4x26x, as now x265 is officially supported.

However, the x265 style "x265 <infile> <outfile>" is not supported and probably never will. You need to use -o or --output before outfile.
0.10.0 tagging
Support automatically invoke DGSourceIM
Cleanup gcc warnings, and build x64 version