We are using a different appid when building for development. By setting
the profle=development meson changes the appid to the devel appid.

This also changes the behavior of profile: always use
`org.gnome.Contacts` and only when profile=development use the devel
appid.

* Replace `join_paths` with the `/` operator
* Remove some unused config variables
* Use `@BASENAME@` when it makes sense

This is required to build with current libhandy

Seems I forgot to commit part of my last fix.

See #122

This fixes RTL direction support of Hdy.Leaflet.

When using libhandy as a subproject, we use its `libhandy_dep` variable,
which doesn't contain the VAPI. Normally, this would be handled by
pkg-config, but since that's not used here, make sure we add it
ourselves.

This will be needed to use Hdy.init() in the next commit.

This should make it easier for build processes (like package builds)
that run entirely offline to have the dependency available.

We'd like to get rid of this submodule in the next release, but I guess
it can't be avoided for now.

Fixes #120

We actually already assumed this when building docs.

This is the first version to offer the 'use-markup' property for
Gtk.ModelButton, which is going to be used in the next commit.

* Have a very basic test that calls something from Contacts.Utils, so we
know that it was able to properly compile and link.

* Some function access modifiers had to be changed to public, or they
wouldn't be recoginzed outside of the static library.

* Also make sure our CI actually runs the tests.

Fixes #95.

This is against the GNOME Meson guidelines.

Fixes #91.

It's easier to keep them in sync with meson_options.txt this way.

We won't them by defaul though, you have to explicitly set 'docs' to
true when configuring meson.

Hurray! \o/