Add unicode support for console output on windows

Hints regarding the unicode support were taken from the libuv project, which
really helped.

Conflicts:
	src/base/system.c
Fix compilation on windows

const int wasn't detected as compile-time constant.
Only use WriteConsoleW if the intended output is the console

Conflicts:
	src/base/system.c
Disable map sounds with snd_enable 0 as well (fixes #98)
Don't add duplicate skins (fixes #102)
Code cleanup
Broadcast about DDNet client delayed a bit (fixes #72)
Add an option to assume demos to be race demos
Make detail flag work for sounds (fixes #103)
More time for double click recognition (0.33 instead of 0.25 seconds) (fixes #17)
Add sv_solo_server for easier solo servers (also working for tunezones finally)
Remove magic number: 256 -> NUM_TUNINGZONES
Version 6.3
Disregard whitespaces in confusable name comparison
Remove log that happens too often
Keep retrying for FifoFile even if it's temporarily unavailable
comment
Remove another bad log
Send timeout code later (fixes timeout code entering issues, fixes timeout protection not working realiably with dummy)
Merge remote-tracking branch 'def/DDRace64' into multibind