avoid making AIS theta calculations if they are immediately discarded
refactor ais drawing code from chcanv.cpp to ais.cpp
simplify ais rendering logic, and reduce redundant calculations
Correct S57 AREA object selection logic when using VBO
Correct 0-360 sectored light display (FS#1437)
Correct Route Reverse Cancel option  FS#1436
Improve performance of unrotated OpenGL raster symbols.
programatically support n-bells eliminating 3-8bells.wav thus reducing package size
Correct inadvertent overwrite of SENCFileLocation in config file. FS#1408
Merge branch 'master' of https://github.com/OpenCPN/OpenCPN into reduced-bells
use wxDC#IsOk instead of (at least in wxwidget3.0 non-existent) wxDC#Ok
Fix int->void* conversion that is invalid for 64bit systems
Correct hang with Touch Screen interface on route edit.
Correct sounding render inclusion test.
Merge pull request #146 from seandepagnier/reduced-bells

Reduced bells
Merge pull request #147 from seandepagnier/ais_optimizations

AIS optimizations
Merge pull request #148 from nkiesel/master

use wxDC#IsOk instead of (at least in wxwidget3.0 non-existent) wxDC#Ok
Correct OpenGL symbol texture loading logic
Improve performance of OpenGL raster symbol rendering
Improve OpenGL setup log messages.