new plugin: layer-count

fixes #821
website: update faq
- remove now outdated 'iphone' references
- add details about the niantic invisible portal issue to the existing faq entry
use predefined constants
updated comments
[portals-list] rewrite large parts, making it more extensible
[portals-list] updated comment
[keys] show keys in portals-list
[uniques] show visited/capture state in portals-list
[portals-list] Fix filter on mobile
[keys] fix layout of buttons in portals-list on mobile
[bookmarks-by-zaso] support for stars in portals-list
[portals-list] bugfix
player tracker plugin
- rename pguid to plrname - players haven't had GUIDs for ages, and it's easy to confuse with portal GUIDs
- portal GUIDs removed. create a temporary unique string from the portal lat/lng - will be fine for player tracker itself
[uniques] Disable COMM parsing for now, since GUIDs have been removed
[uniques] forgot to bump version
Merge pull request #866 from fkloft/layercount

new plugin: layer count
Merge pull request #867 from fkloft/portals-list

new framework for portals-list
Remove old hook
implement latlng-to-guid cache
[uniques] Use position-to-guid cache