VFW encoder plugin for PlayClaw 6

1. Create a folder called "plugins" under C:\Program Files (x86)\PlayClaw 6\
2. Copy the encoder-vfw.dll file to the plugins folder: C:\Program Files (x86)\PlayClaw 6\plugins\

Compilation requires the PlayClaw 6 SDK: https://github.com/CyberDemonLord/playclaw6-sdk

1. Copy the VFW encoder plugin source files into playclaw6-sdk\source code\plugins\encoder-vfw\
2. Add the encoder-vfw.vcxproj file to the playclaw6-plugins.sln solution
3. Open the solution with Visual Studio 2015/2017, migrate/retarget as necessary then compile