Experimental Mac package

[Dirk Hohndel]

If you’d like to help test the Mac version of subsurface, please 
head over to the Downloads page and test the DMG that I have provided there.
http://subsurface.hohndel.org/downloads/

There are a number of different possible ways one could package a gtk 
application for the Mac – and I don’t really like any of them. So I decided 
to invent a new one… this one contains a somewhat cut down (but likely 
still too rich) custom build of gtk, libusb and libdivecomputer that are all 
installed inside of the actual application. Because of that I am almost 
certain that this will NOT work unless the application inside this DMG 
is copied to the /Applications folder.

I am open to suggestions for improvements to the packaging process, 
as long as they don't involve the user downloading and installing any
other package first - that to me is not an option.

/D