Better instructions for translates to receive credit in the About
dialog (#5911) and includes strings in the Preferences dialog in
the .pot file. Also removes unneeded Translations.cmake file
(Gettext.cmake has all that we need) and fixes a problem in a late
release update for generating the POT file.
./configure will autodetect xgettext, and if available, "make pot_file"
will generate the po/geary.pot.
This does *not* include intltool support, so the .pot file only
contains strings from the source files.