fix #3007: Support Geokrety 'DO NOT MERGE'

fix #4315: Add an icon to trackable representing "brand"
fix #4326: GeoKrety, some details are missing

* Load Geokrety Async while loading a cache
* Store brand into database
* rework xml parsing a bit on geokretyparser
* Create settings->service->Geokrety
* Load GK only if setting is active
* Add setting option to use GeokretyMap cache
* Make Geokrety loggable
* reworked LogTrackableActivity
* differenciate LogType and LogTypeTrackable
* Implement TrackableLoggingManager(s)
* Show GK in LogCacheActivity
* Implement GeokretyInventoryLoader
* Geokrety can be dropped in any loggable cache
* Moved Loaders to specific file. prevent loadersId conflict
* Geokretymap provides for some geokrety details infos
* Use geocode for accessing Geokret from LogCacheActivity
* Add geocode to TrackableLog


As discussed on IRC, here is some work for supporting GK.
Tests should pass.
I still have to write more unit tests.

I know there will be much to say.
Thanks for reviewing...