based on a snippet by @Earnestly

aur-build: fix db_name/db_root argument order

7c648601 removed setting db_root from
pacman.conf if db_name was not set, in the assumption that db_root would
be set in the pacman-conf loop. However, latter is only done if db_name
is specified with -d. Revert this commit.

Fixes #795

Fixes #795

aur-repo: set repository extension with AUR_DBEXT

Instead of keeping a second repository selection logic in aur-build
(with slight differences to the one from aur-repo), simply forward the
-d and -r arguments to aur-repo, unless both are set. In particular,
aur-build can now be used with only the -r argument set.

This is achieved with the new aur-repo --status option (colon-delimited
output of repository name, path and root), which replaces aur repo --path.

aur-vercmp takes 2-column input.

For example if custom.db is not a symlink (on file systems not
supporting them) but a regular file:

  $ AUR_DBEXT=db.tar.gz aur repo -d custom
  /path/to/repo/custom.db.tar.gz

  $ aur repo -d custom
  /path/to/repo/custom.db

To achieve this in aur-sync, extend --status-file to include the
repository path.

If the path passed to --results is a relative path, aur-build would
write it to the package directory ($PWD/<package>). To avoid
this, resolve the path before changing directory.

To avoid future mistakes when changing directories, also resolve the
path in aur-fetch.

aur-sync: add --provides-deep

Allows to print a diagnostic to the screen on which transitive
dependencies were filtered out.

Allows to take transitive dependencies into account.

Fixes #592

aur: fix substitution of AUR_LIB_DIR

Only required for the install step

aur: add --version output

When installing aurutils from a tarball, git describe is not available.
Include a string that is updated on each release instead.

If wanting to support different aurutils versions in the same script,
having the version directly from `aur` can be useful. (e.g. if
aurutils is installed manually through the Makefile)

aurutils: release 3.1

These are not supported and can cause issues (e.g. when using libmakepkg
instead of makepkg --packagelist)

Fixes #782

Clarify the purpose (partial order) and extend the examples.

Based on documentation in archlinux/contrib:

https://github.com/archlinux/contrib/blob/master/package/srcinfo-pkg-graph

Issue #783

The --ini output was incomplete, only listing repository name and Server
directive, and a list of paths is more convenient to use directly. In
particular, use --path-list for the documented aur-remove script.

The documentation in aur-repo.1 was outdated in other ways, remedy this
as well.

Fixes #784
Fixes #785

Temporary measure until a temporary (user-modifiable) environment can be
used instead of modifying the host.

aur-chroot: add base-devel to multilib container

aur-chroot: add --create

* Add --create which solely runs mkarchroot (and creation of parent
  directories). Compared to --update, this allows the user to specify
  the installed package(s) (groups) directly on the command-line

* If no packages are specified after --create, default to base-devel or
  multilib-devel depending if the pacman configuration (--pacman-conf)
  has a [multilib] section. This is done with pacini (instead of pacconf)
  due to devtools not supporting Include directives.

* When running --update, add a directory check and reminder to run
  aur-chroot --create.

* Add wait $! after pacman-conf to preserve the exit status.

* Let --packagelist read the makepkg.conf inside the container
  (depending on its directory), rather than a fixed path to makepkg.conf
  on the host.

This does not require users to write files to /usr/share and allows to
have several pacman.conf files with --chroot (per repository) without
requiring --pacman-conf.

lib: use /tmp/aurutils/$UID for temporary files