Added a D-BUS service to create and extract archives.

Initial commits from FR:
f998fd8e33a08d686a1071db87d21f4a83963d99
4078d1a9e5ddae3357302791432fc61d82ff37e4
58c55b06f30014326f27bdf94c406ceee0897731

Improvements and fixes from FR:
D-Bus service: added GetSupportedTypes method
ace4f31c586641fcf7ad1de165cd7f27b5a371c1
1399b9a84b0d4f4a5015066b0d7cec7e048d59dc

From: Paolo Bacchilega <paobac@src.gnome.org>
do not call release_data if the data was not initialized

Based on FR commit: 	05c0b2c366f5524645167d9dca2268219563559d
From: Paolo Bacchilega <paobac@src.gnome.org>
set a fixed title for the progress dialog

Based on commit: fd497f4f9db806ce97f68d0366ae1f7fd37eccd1
From: Paolo Bacchilega <paobac@src.gnome.org>
Fix warnings