Update erltrek.hrl

* Remove ?GALAXYCOORD()

* Change ?QUADCOORD() and ?SECTCOORD() to handle records
Update erltrek.hrl

* Change macros ?QUADCOORD() and ?SECTCOORD() to erltrek_setup:[quadxy_index/1, sectxy_index/1]
Update erltrek_setup.erl

* Change macros ?QUADCOORD() and ?SECTCOORD() to quadxy_index/1, sectxy_index/1

* Remove redundant code

Add @todo