Update "Bookmarks".  New "Portals Exporter".

Update  "Bookmarks":
- fixed some bugs;
- optimized code to get portals/maps data
- Added panel for export, import and reset the bookmarks;
- Added the 'star' (to add a portal in bookmarks) in the new mobile
status bar;

New "Portals Exporter". Generate a kml structure to import into Google
Maps or Google Drive:
- Export portals;
- Customize caption (address, image, coordinates);
- Filters by owner faction and levels;
- Support to Bookmarks plugin (export one or more folders from the
Portals Bookmarks);