Use program directory as current directory

And do that as soon as we can.
Fixes #3495
build.bat: Fix /GetVersion after recent changes
UpdateChecker: work around git-describe issue
player.html: remove width completely.

It's handled in JS.
Enable per-monitor DPI-aware on Windows 8.1.

Fixes #3356.
temp
Use ZeroMemory on more places instead of {0,0}
Fix NULL handle passed as parameter.
Update Git to 1.8.4.
Cleanup