Improve  DSC message decoding and display.
Merge pull request #137 from seandepagnier/master

fix the build for windows
Improve  DSC message decoding and display.
Merge branch 'test'
Refine DSC Message processing and display
Improve GPSGate Buddy message reporting.
Establish soft memory limit for linux systems as 50% of available RAM
Merge branch 'master' of https://github.com/OpenCPN/OpenCPN