Add Is8OrLater() and use that in the places we checked for Windows 8.

Fixes ticket #3411.
Build.bat: Support for debug packages.
Put back removed string in mplayerc.eu.rc.txt after 8608c253a918f63586d88d3ed7bb285924957163.
player.html: remove width completely.

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

Fixes #3356.
Add a Doxyfile to generate source doc.

WIP
Use DEBUG_NEW instead of new.
temp