Fix warnings on 32 bit systems

- Change format specifiers to not make assumptions about integer and
  size_t sizes
- Change audio hash function to shift a different amount based on
  sizeof(size_t)
Merge pull request #151 from blucoat/32bitfix

misc: fix warnings on 32 bit systems
buildsystem: fixed install path issues from #81
pathfinding with many units on a tile
Merge remote-tracking branch 'upstream/master'

Conflicts:
	copying.md