Add more support for Win64: - Export .lib files for x64 instead of i386; - Win64's malloc returns 16-byte aligned blocks.
Add more support for Win64:
- Export .lib files for x64 instead of i386;
- Win64's malloc returns 16-byte aligned blocks.

git-svn-id: a4d7c1866f8397a4106e0b57fc4fbf792bbdaaaf@13147 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

prajnashi/ffmpeg,prajnashi/ffmpeg,prajnashi/ffmpeg,prajnashi/ffmpeg