gdb: patch tui-io.c., adding typedef Function lines
Add patch.
pkgconfig: make sure apps/pkgconfig/share/aclocal/pkg.m4 is in HUL/apps/pkgconfig/share/aclocal/pkg.m4.
libatomic_ops: libtoolize automake and autoconf to generate configure.
bdwgc: import pkg.m4, libtoolize and autogen to generate configure (patched).
Add mcron/.ignorepull, to make pull_external exit early (when testing)

Execute the script without fetching or pushing if there is at least one
parameter (any parameter), when .ignorepull is detected.

If there is no .ignorepull, then operates normally.
Fetch / push when needed.
mcron/pull_external: add timestamp.
mcron/pull_external: make sure reading FETCH_HEAD doesn't trigger en error.