FlightMenu bugfixes, integration

Controls:
-added FlightMenu menu
-initialized in init()
-rendered in render()
-triggered in setSelectedFlight()
-auto-indented

FlightMenu:
-corrected Graphics import to slick.Graphics
-changed graphics data for aesthetics
-image initialisation moved to init()
-corrected indicator drawing to uses IndicatorPos s
-corrected altPosIndicator scaling calculation, now makes use of max AND
min
-inverted altPosIndicator scaling; up is +altitude
-corrected speedPosIndicator to use speedPos as baseline
-corrected headingIndicatorPos to perform radius-shifting after
mid-point calculation
-corrected abort drawing to use abortPos
-updated event routines to trigger Indicator recalculation
!altBase rotation "fixed"
+no way to properly rotate and keep top-left indexing
+limited slick Image operations
+rotation independent of later subsampling...
+altPos shifted +sliderWidth to properly align
+all references to altPos are shifted -sliderWidth to accomodate
!still no mouse support
-auto-indented