Concentrate compiler dependencies to compiler.h; make sure compiler.h
is included first in every .c file (since some prototypes may depend
on the presence of feature request macros.)
Actually use the conditional inclusion of various functions (totally
broken in previous releases.)
- Remove obsolete types like "uint32"; use "uint32_t" consistently.
- Make sure we include <inttypes.h> where needed.
- Header file guards should be FOO_H or SUBDIR_FOO_H; _FOO_H infringes
on the C implementation's namespace and should only be used when
writing libc!
- Change a few "int8_t" back to "char" where appropriate. There are
a lot more places where that should be done, though.
- Clean up the check for getuid/getgid in rdoff/rdlar.h.
