Remove Leaflet map when its directive destroys
Cancel time interval objct in TimeDisplay directive when the directive destroys
Destroy FPS meters in Simular controller when the controller destroys
Update SonarGraph and PlotGraphs
Merge branch 'master' into features/eugene/memory-leaks

Conflicts:
	www/js/game/controllers/simulator/mission.tpl.html
	www/js/game/directives/sonarBearing/sonarBearing.js
	www/js/game/services/plotGraphs/plotGraphs.js
	www/js/game/services/sonarGraph/sonarGraph.js
Fix rzslider directive
Merge pull request #92 from IanMayo/features/eugene/memory-leaks

Eugene's very clever fixes for memory leaks
Change meters/second to knots in UI
make sonar tracks "dirty" according to platform type
tidy objectives, to match new, tidier schema
embryo of sprint-drift mission
introduce new distannce-from-category objective
mature the mission
improve words, update mission index
Fix GeoJSON
part way through bow nulls mission
Allow actual speed to be specified as float, since it may take several seconds to get to new demanded speed.
Merge pull request #93 from IanMayo/features/eugene/knots-display

Great, thanks Eugene.
Merge branch 'master' into feature/ian/updated_scenarios
include missing objective descriptions