Small bugfix for windows users and fixed some demandimport errors. Added correct license informations to the source files, too.

Text messages that include geo coordinates in the format ex: geo:48.2057365,16.3435941
are converted to a preview of the location on Google Maps

Added ability to mark text including image and use copy'n paste to paste this text including the original url. Also removed the encryption settings from filename in save as dialog.

Added right click menu to preview plugin and reorganized code. Also fixed regression regarding thumbnail size and added gtk pixbuf thumbnail generation if pillow isn't available.