Add mimetreeparser to appimage
* configure.ac, src/appimage/Makefile.am: Add packages. * src/appimage/rsync-filters/kcalendarcore.rsync-filter, src/appimage/rsync-filters/libical.rsync-filter, src/appimage/rsync-filters/mimetreeparser.rsync-filter: New.
Currently does not find GPGME when compiling mimetreeparser.