Require at least glib-2.32

g_hash_table_contains was introduced in 2.32 according to
https://developer.gnome.org/glib/stable/glib-Hash-Tables.html

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Require at least libmtp 1.1.2

... as stated in the README.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Set version 2.0

... as stated in the NEWS file.

Signed-off-by: Olaf Hering <olaf@aepfle.de>