pidgin/pidgin

Use the G_DECLARE_*_TYPE macros for JabberProtocol and XMPPProtocol

Testing Done:
Connected an XMPP account.

Reviewed at https://reviews.imfreedom.org/r/618/
pidgin3_xml = configure_file(
input : 'pidgin3.xml.in',
output : 'pidgin3.xml',
configuration : version_conf,
install : true,
install_dir : get_option('datadir') / 'glade/catalogs')