OpenXcom: add a SOURCE_FILENAME, use a nicer SOURCE_URI.
OpenXcom: add a SOURCE_FILENAME, use a nicer SOURCE_URI.

Begasus/haikuports,haikuports/haikuports,moochris/haikuports,nielx/haikuports,haikuports/haikuports,moochris/haikuports,moochris/haikuports,Begasus/haikuports,nielx/haikuports,nielx/haikuports,Begasus/haikuports,Begasus/haikuports,haikuports/haikuports,Begasus/haikuports,haikuports/haikuports,haikuports/haikuports