During the build process there is one case when parts (source files) are
located in different directories and then linked together. Dependencies
are specified seemingly correctly, but the problem is that the build rule
`$(CC) $(CFLAGS) -c $*.c' loses information about source file path due to
how `$*' is expanded ("no suffix or preceding directory components") and
does not specify output object path.
Change it to more robust and correct `$(CC) $(CFLAGS) -o $@ -c $<' as a
remedy. Since this is BSD syntax, remove `gmake' from USES.
Tested by: marino (looks good, but not a complete guarantee)
6ce56e5c81