adding more tests.
test for build()
test for scale_number()
update submodules
reorganized directory structure.
flattening the directory structure, moving some modules to the src/ directory.
making stealth a separate file, under test.
more tests for some stuff.
add a test for the vortex special direction before touching that code.
refactoring: special directions into their own file (vortex.c).
moving spells.c out of spells.
figured that movewhere should be in move.c
In the game, there is only ever one special direction, and it is for the astral space.
less XML, more code.
cleaning up the special direction parsing a bit.
peasant blood should not have ill effects on non-demon units that are empty.
This fixes http://bugs.eressea.de/view.php?id=1981
fixing linux build