pidgin/pidgin

Pull the purple_markup_* api out of util.[ch] to purplemarkup.[ch]. No code was changed just moved it from one file to the other.

Testing Done:
Compile and unit tests.

Reviewed at https://reviews.imfreedom.org/r/171/
pidgin3_xml = configure_file(
input : 'pidgin3.xml.in',
output : 'pidgin3.xml',
configuration : version_conf,
install : true,
install_dir : get_option('datadir') / 'glade/catalogs')