Update erltrek_calc.erl

* Refactor sector_course/2 and sector_distance/2 to use sector_course_distance/2, remove duplicate code
Update erltrek_klingon.erl

* Fix typo Attach -> Attack
Update erltrek_phaser.erl

* Remove debug print of SDIST/SCOURSE in hit_phaser/6

* Notify only when phaser hit level > 0 in hit_phaser/6
Update erltrek_scan.erl

* Remove trailing whitespace

* Add adjacent_sector_contents/3
Update erltrek_scan.erl

* Add comment of adjacent_sector_contents/3
Update erltrek_klingon.erl

* Add actual_move/1 test code, still coding...
Update erltrek_klingon.erl

* Add more actual_move/1 test code, still coding...
Update erltrek_klingon.erl

* Add notification of klingon move in actual_move/1
Update erltrek_terminal.erl

* Add {klingon_move,...} in handle_event/2