more silencing warnings with casts

also:
- separate targets for gamepal and signon, in both Xcode and the top
Makefile
- actually use Automake features
- more configure checks
- clang-specific makefile for wolfextractor
- more printf-style debugging statements
- add more files from gnulib, and give its subdirectory its own Makefile
- other changes resulting from debugging (mostly for wolfextractor)
- silence other warnings other ways
C
B
C
A
D
C
B
A
C
D
B
C
B
D
B
D
A
B
A