experience points calculation
Ignore Xcode project/workspace user data
Fix Xcode build

* added OpenGL framework to libraries
* removed dubious header search path pointing to an absolute path
inside Xcode.app
MacPorts support for Xcode build

* added MacPorts library and include paths to search path
* updated build instructions in README to explain how to install
dependencies with MacPorts
fix inconsistent value
Merge pull request #1 from SupSuper/master

sync
radar stuff

correct some values, externalize others.
oversight: default isn't 0
minor optimization
Merge pull request #2 from SupSuper/master

sync
Fixed craft speed not matching UFO speed during dogfights.
Long names fix
Merge pull request #913 from GixG/UfopediaCraftTitle

Fix for bug report #785
Fix for issue #771 (Psi attack breaking targeting mode).
fix incorrect craft rearming
fix explosions
Fix BR 779
Update CraftArmorState.cpp
Update SoldierArmorState.cpp
Update SavedGame.cpp