Refactoring: FontMgr as a singleton instead of a global variable.
Merge pull request #62 from mariokonrad/refactor

Refactoring: FontMgr as a singleton instead of a global variable.
Implement pugiXML for improved navobj file performance
Port the possibility to turn off OpenGL completely from 3.2.2
Replace degree signs in the code with proper unicode encoded representation
Implement a hotkey (Ctrl+I) to hide/show GPS status indicator - FS#1001
Implement the possibility to drop waypoint on the current position of an AIS target from the target list/query dialog
Implement (M)ARPA radar targets tracking (TTM and TLL sentences) and AIS-like display, implement optional APRS position report tracking (uses WPL sentence) and AIS-like display (FS#964)
Take file's time steps when "interpolate" option is uncheked and improve timeline scrolling
Merge pull request #67 from Ptizef/master

 Take file's time steps when "interpolate" option is uncheked and improve timeline scrolling
Improve grib data panel (Add unit symbols and use all space available for data)
Merge pull request #68 from Ptizef/master

Improve grib data panel ( Add unit symbols and use all available space for data )
Correct SENC Text formatting
Optimize layer trackpoint listing logic in RouteManagerDialog
Improve performance of track rendering at small scale.
Improve NavObjChanges logic to prevent infinite looping
Fix ARPA target reference heading logic
GribUIDialogBase files are now generated with wxFormBuilder
Correct Grib dialog position persistence & suppress  double grib dialog display
Implement a hotkey (Ctrl-N) to activate next waypoint in the active route (FS#1010)