Use `foo/bar.a' instead of `-Lfoo -lbar' for linking to static internal

Use `foo/bar.a' instead of `-Lfoo -lbar' for linking to static internal
libraries so that `ld -f' in can create correct dependencies for
yet-to-be-built libraries.

Get the default BINDIR correctly (by including ../Makefile.inc recursively.
Override the default it it is wrong.

Don't override defaults when the defaults are correct.

Don't give absolute paths to man page sources.