MaxOSX: settings fixes (#2371)

- Launch-At-Startup implementation for mac
- Remove "Window" tab in settings

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>
Merge branch 'master' of git://github.com/bitcoin/bitcoin into prefsFix

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>

Conflicts:
	bitcoin-qt.pro
Merge pull request #2613 from jonasschnelli/prefsFix

MaxOSX: settings fixes (#2371)