dbglog: Added seperate macro for enabling debug log. Receive ERR message on all channels by default.

You still need to register the channel in the usual way to receive both MSG and ERR messages.
OGAMEMP: Added dbglog channel GameMP
OLOG: Add GetTickCount()-time to debug message (Windows only)
Multiplayer: Fixed major sync issue in is_mp_sync

This issue was introduced in "96101eed6ad Implement network support using enet"
is_mp_sync was not waiting when not all players were ready.
OBATTLE: Let the host determine initial gamespeed for all clients.
Merge branch 'MicroVirus-is_mp_sync_fix'