more test coverage for resource pooling.
add missing tests for groups.
Assert that magicians are single-person units in a few places.
Bug 2028 claims that this is not always the case, though I cannot prove it.
fix segmentation fault in test.
Merge branch 'master' of github.com:badgerman/eressea
fix segmentation fault in new assert (units without a faction)
refactoring modules, cleaning out the config.c kitchen sink.

- cansee_* rules to laws.c
- translations to language.c
- stealth to attributes/,
- rename build.h -> buildno.h
move magic out of kernel, into src.
clean up/remove a ton of includes, especially of types.h (include in header if you need it, not in every .c file).
fix gcc build, forward-declare structs in the header.

MSVC allows structs to be declared in a function signature, gcc wants
to know about them earlier.
refactor config.c, move the find* functions into the modules they belong to.
Merge branch 'master' of github.com:eressea/server
Merge pull request #48 from badgerman/master

more refactoring, no new features.