Fix a few things related to the translations
Update the german translation
Du/Sie consistency
Update mmc_de.ts

Fixed grammar, improved wording.
It's not perfect but definitely better.
Add xnrand to the translation credits
Clean up/update translation code and made language selectable in the settings dialog
Hopefully fix Qt 5.1 compilation
Unbreak and reactivate the some UpdateChecker tests
Get rid of some obsolete functions
Hopefully fix OSX icon file
Add logging calls to the java checker.
Merge branch 'develop' of github.com:MultiMC/MultiMC5 into develop
Merge branch 'master' into develop
Make the GitHub link in the about dialog clickable

Fixes #38
Add "MB" as a suffix to memory spinboxes
Merge branch 'develop' of github.com:MultiMC/MultiMC5 into develop
Hide user properties in the console too
Add tooltips to Java memory spinboxes
Make CacheDownload use QSaveFile
Show active account skin whilst it's checked for updates