o main returns int not void
o use return 0 at end of main when needed
o use braces to avoid potentially ambiguous else
o don't default to type int
o #ifdef 0 -> #if 0
Reviewed by: obrien and chuckr
"." means the object directory, so it is just confusing to use it
when nothing is included from the object directory unless the object
directory is also the source directory. It is confusing for "."
not to mean the source directory anyway, so used `-I.'s should be
replaced by `-I${.OBJDIR}'.
