Cherry picked from 4a91d5ee
(Add translation support for short names of Emoji and other symbols)

and 851b3afb.
(l10ntools: support x-comments in ulf format).

See also https://wiki.documentfoundation.org/Emoji

Change-Id: I3d7ec13d381160d63d535ccbdcd0b3209799d3d5
Reviewed-on: https://gerrit.libreoffice.org/16014Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>