gpsd: update 2.95 -> 3.10

Build system is changed, gpsd uses scons now.

The expressions needs some more work, TODO comments added. (xgps didn't
work before this change either.)

I added an option for the gpsd group, which is set to upstream default:
"dialout". Note that our default gpsd user is "gpsd", while upstream
uses "nobody" by default.
gpsd: update meta attributes

* Don't repeat package name in description
* longDescription re-copied from homepage (gpsd now supports AIS...)
* The homepage has moved
* Add platforms and maintainers