Don't displace objects when they are duplicated.
Paste objects either in their original position (if nothing is selected)
or in a position such that their center is identical to the center
of the selected objects.
Fix issues with mod dir dropdown being off by one.
Fix minor issue with the Windows build scripts.
Merge branch 'Release_1.0.0'

Signed-off-by: Kristian Duske <kristian.duske@gmail.com>

Conflicts:
	Mac/TrenchBroom/TrenchBroom-Info.plist
	Windows/TrenchBroom/BuildNo