implicit declarations, redundant redeclarations, missing initializers,
nested externs and other cruft.
Cleaned up includes and moved extern _Type decls from Types.h into
Types.c since that is the only place where they are needed now.
Did not touch Ipo.[ch] since work is on-going there.
- Mostly this cleans up the #includes and header files in the python project.
- Warning fixes are mostly casting issues and misc fixes. General warning clean up.
- #include Python.h MUST come as the first include to avoid the POSIX redefine warning in the unix makefiles
- fno-strict-aliasing flag added to makefile to fix a unavoidable type punning warning in types.c
