fixes for compiler warnings

work in progress on cleaning up code so it can be compiled
with the same set of warning flags used on Darwin. This is an initial
pass through the C files in src to resolve warnings. Most warnings
are related to implicit size/sign conversions between integral types and
missing explicit prototypes for non-static functions.

Signed-off-by: Daniel A. Steffen <dsteffen@apple.com>
12 files changed