Update OSX app icon.
Add Game Monitor

Add Game Monitor and update sln.
This also removes CrashDialog
Disable internal Error Message

Rely on GameMonitor to display error message.
Update Windows installer and Makefile

Update windows installer to point to OpenRA.exe
replace CrashDialog with GameMonitor in MakeFile
Fix packaging scripts
Remove Unused Settings

This removes unused settings related to CrashDialog
Add crash dialog to OSX launcher.
Add crash dialog to Linux launcher.