Clean code, bug fixes

Split messages.cpp in 4 files and widget.cpp in 2 files.

Fix SEGFAULT on exit that happenned while disconnecting every player.
Fix SEGFAULT on exit in ~QApplication (now we just quick_exit after a small cleanup in ~Widget)

Fix CPU exhaustion caused by QByteArray::toHex() in log messages. We now use less log messages.
Fixes #9

Move the timer restarts in the locked (via mutex) sections.
Hopefully fixes the deadlock in issue #8, but this needs testing.
Log messages were added before every lock/unlock.

Add command "dbgStressLoad" that sends every player in the GemMine at the same time.