This reverts commit 497ab047.

They want new e-d-s running. No thanks.

#56

Closes !10

It has been wrong since the autotools times, and apparently nobody has
noticed. Why bother documenting the library in the first place?
Signed-off-by: Philip Withnall <withnall@endlessm.com>

Fixes: #108

This gives issues for people that don't have their python2 binary at
`/usr/bin/python2`. The cleanest way to solve this is to just use
`/usr/bin/env python2`

Fixes GNOME/folks#107

it’s been dead for years

It was deprecated quite some time ago in favor the simpler GTask API.

`GSimpleAsyncResult` has been deprecated in favor of the simple GTask
API quite some time ago.

Due to the way `TpMutableContactGroupListInterface` is set up, we now
also have to implement the `_finish` functions (since we don't use the
default GSimpleAsyncResult implementation anymore). Luckily, the
functions have the same signature, so we can just reuse one function
here.

This gets rid of some GObject boilerplate, while simultaneously fixing a
deprecation warning (due to the use of `g_type_class_add_private`).

This was deprecated a long time ago (since GLib 2.36) and no longer does
anything. Fixes a deprecation warning.

This fixes a valac warning.

This fixes a few valac warnings.

This fixes a valac warning when compiling the libsocialweb backend.

This was needed in the automake build, but since we've added support for
Meson now, we can just rely on the `--gdb` option of `meson test` to
start up a gdb instance for us (and G_DEBUG=fatal-warnings to let us
break at the correct point).

!13

Maintaining Autotools as a build system is very, very heavy on
maintenance. Let's drop this for the next big release so we can focus on
the bugs that truly matter.

!13

And update them to use Meson conventions for testing and building rather
than autotools-related ones.

List the build dependencies directly so we don't pull in unintended
dependencies (like intltool) and can add the ones we want (for example
meson and ninja-build).

It is good practice to specify the version in any case, and since it
still uses python 2, we might as well be explicit about it adding a
dependency to python2.

Use the name() method from the dependency objects themselves, which is
more foolproof in case of an update and makes sure we don't refer to
dependencies we shouldn't be using.

Fixes #105

Because some backend libraries have a different VAPI/GIR namespace, we
need to make sure this doesn't get omitted in the generated VAPI files.
See the comments in the code for more info.

Spotted by @ricotz at !9 (comment 491440)

The generation of the tracker backend typelib,
`FolksTracker-0.6.typelib` fails because `Folks-0.6.gir` cannot be
found.

This has been fixed by including `folks` build directory so the
`Folks-0.6.gir` file can be found.

See the [Meson website] for a full reference. To build, test and/or
install the folks library, you essentially need the following commands:

```
$ meson build
$ ninja -C build
$ meson test -C build
$ ninja -C build install
```

Note that there is no one-on-one mapping sometimes from the autotools build to
the meson build definitions, so here's a non-comprehensive list of changes:

* Vala support is now mandatory.
* Since meson doesn't have libtool's `export-symbols-regex`, we need to
write our own little linker script to make sure we're not accidentally
exporting symbols we shouldn't be exposing (such as
_libfolks-internal_'s functions).
* Meson has [built-in support for lcov], see the online reference for more info.
* Meson also has built-in support for Valgrind by adding the `--wrap=valgrind`
option.
* There is no wildcard support in Meson (for good reasons), so instead
we need to re-use the definitions found in the backend library's
meson.build files to have the correct source files for the valadoc
modules.

[Meson website]: http://mesonbuild.com/
[built-in support for lcov]: http://mesonbuild.com/Unit-tests.html#coverage

It actually makes valadoc error out with the message:

> unexpected token: <space>

[CCode (finish_function = "...")] is deprecated, use [CCode (finish_name = "...")] instead.
finish_function is deprecated since a long time now.

warning: DBus methods are recommended to throw at least `GLib.Error' or `GLib.DBusError, GLib.IOError'
This has always been an issue, the compiler warns since a few years now that this is required.