Packages: Fix OSG3 compilation issues on OSX 10.8

Requires you to use crappy Apple compiler or one of the newer Clangs
(Hooray 3.3). The reason for this is that it apears osg3 is using some
Objective-C.
whitelist: Don't ship OSG DB
BB.py: Remove repeated flags inside environment

This will remove all the repeated includes we have. I don't think this
is a performance benefit. It is only to increase the ease of reading
the compiler flags.
Packages.py: Expand dependencies of ISIS