Recent development versions of makepkg support reproducible builds
through the environment variable SOURCE_DATE_EPOCH. Pass this variable
through makechrootpkg to makepkg when available.

Also initialize SOURCE_DATE_EPOCH whenever running archbuild to enforce
reproducible builds for repository packages.

Signed-off-by: Eli Schwartz <eschwartz@archlinux.org>
Signed-off-by: Levente Polyak <anthraxx@archlinux.org>

This involves extending the signature of lib/common.sh's `stat_busy()`,
`lock()`, and `slock()`. The `mesg=$1; shift` in stat_busy even suggests
that this is what was originally intended from it.

In cases where there is no license specified, the file is tagged as
"License: Unspecified".  Obviously, that is not ideal, but it
highlights the fact, and I hope that it encourages whoever has the
authority to specify the license to do so.

On that note, to anyone who may have the authority to specify the
license of files in devtools: the current licence of many files is
GPLv2 with no option for later versions; I impore you to re-license
them to have the "or any later version" option.

`lock_close FD` is easier to remember than 'exec FD>&-`; and is especially
easier if FD is a variable (though that isn't actually taken advantage of
here).

This uses Bash 4.1+ `exec {var}>&-`, rather than the clunkier
`eval exec "$var>&-"` that was necessary in older versions of Bash.
Thanks to Dave Reisner for pointing this new bit of syntax out to me
the last time I submitted this (back in 2014, 4.1 had just come out).

The systemd package creates a subvolume at /var/lib/machines (through
tmpfiles), if it can. We need to delete this subvolume before we can
delete the parent subvolume.

Look through the root for inodes with the number 256. These identify
subvolume roots.

Move the function and save the orig_argv right along it.

- Uses now systemd-nspawn, so its not compatible with openrc.
- Added bash and zsh completion.
- mkarchroot (mkmanjaroroot) lost the -b (branch) -a (arch) options instead you should copy the correct files using -M for makepkg (arch) or -S for pacman-mirrors (branch). The archbuild (manjarobuild) script have been updated to follow this.
- makechrootpkg also lost the -b option (branch), instead it should point to a chroot with the correct branch and other config files already set.
- manjarobuild and mkmanjaroroot are now symlinks to archbuild and mkarchroot (to keep differences from upstream to a minimum).
- Includes all fixes and updates between upstream devtools-20130408 and devtools-20141024.