Exclude _mysql.pyd from main Panda3D package, to reduce file size
Fix threaded build with Python 2.5, fix OS X build that doesn't specify sysroot
try and remove unnecessary X11 dependency on OS X
a tiny optimisation to use less registers
Don't rely on color fregs, they have unintended side-effects.  Also, don't use up unnecessary registers when texgen is enabled.
Fix blunder
Add SetRegView so we can correctly install 64-bit build to the 64-bit registry
Use 64-bit regview when making 64-bit builds to fix interaction between Python installations/libraries and Panda3D
Move SetRegView to appropriate sections
there's no reason to interrogate the ffmpeg code.