pidgin/pidgin

Move PurpleChatUser to it's own file and fix a few issues with the docs and translations

Move PurpleChatUser to its own file. Also fixed po/POTFILES.in

Testing Done:
Compiled and ran. ChatUser flags are not displayed but they also are not displayed on default right now either.

Reviewed at https://reviews.imfreedom.org/r/78/
if ENABLE_DOC
subdir('reference')
endif
if ENABLE_GTK
pidgin_man = configure_file(
input : 'pidgin3.1.in',
output : 'pidgin3.1',
configuration : man_conf,
install : true,
install_dir : get_option('mandir') + '/man1')
endif
if enable_consoleui
finch_man = configure_file(
input : 'finch3.1.in',
output : 'finch3.1',
configuration : man_conf,
install : true,
install_dir : get_option('mandir') + '/man1')
endif