Log Message:
pluma: update to 1.22

### pluma 1.22.0

    tx: sync with transifex
    Add update-authors.pl script which helps to update pluma.about
    Read authors (updated) from pluma.about file
    show enchant version when configure
    Replace the deprecated enchant_dict_add_to_pwl with enchant_dict_add.
    Make translatable the documenters in the about dialog
    Ensure proper translation of the about dialog title
    initial travis support
    Add License button in About Pluma dialog
    Make translatable the copyright in about dialog
    Update Documenters
    remove type & url attr of ulink in translation
    remove deprecated help section: Opening a File from a URI
    eggsmclient: avoid deprecated 'g_type_class_add_private'
    addresses #391 - gets snippet window size before destroying it
    simple bug fix of misplaced underscore
    disable deprecation warnings for distcheck
    move appdata to metainfo directory
    pluma-utils: Fix memory leak
    pluma-window: Fix memory leaks