Implement crash handling on Linux

This will allow us to generate crash dumps and have users report
crashes.
Remove some unnecessary dummy functions.
Change dump file extension
Implement crash report system on Windows.
Implement backtraces on Windows.

Much !!FUN!! was had
Remove unused function
Fix stupid tabs.

Thanks, QtCreator... ._.
Add a missing letter
Restore manage screenshots in main window.
Merge branch 'feature_crashreport' into develop
FTB paths changed on windows. Fixes #255
Merge pull request #275 from MultiMC/feature_ftb_new_paths

Fix FTB paths on windows
QDir::exists is not static in Qt 5.1.1
Some more FTB related debug info
More FTB debug stuff
Fix FTB?
Attempt at fixing FTB
Still trying to fix FTB
Tagging 0.3.6
Begin the transformation!

Nuke all the things.