Package dSYM along with ipa

Hey,

I have a patch here that'll move the dsym for the current build along with .ipa on the package target.
dSYMs are pretty important for debugging production crashes and not everybody uses TestFlightApp for that, so I figured it'd be pretty useful to package them along.

Patch is fairly simple, added a synthetic getter to get the path to the dSYM folder and one line to move it along with the ipa.
Let met know if I should change anything.

/kra