correct handling of rotated cache in dc mode
Revert "Correct and harmonize raster chart region calculation for skewed charts."

This reverts commit c469bbd66ae0fc6c1854c58816b78985b920ae94.
Consistent install locations for plugins
Implement selectable scaled vector chart symbol rendering.
Correct occasional error in Lights, Text, and Soundings toggle for vector charts.
Eliminate a variety of small shutdown and runtime memory leaks.
Correct a small but persistent memory leak in OCPNRegion dtor.
Improve AIS Target Query dialog layout & colour.
Merge pull request #209 from seandepagnier/master

Correct broken rotated or course up display in single chart DC mode.
Remove F9 quilt mode toggle key in favor of "Q" key.
Correct OpenGL display parameters on overzoom emphasis.
Correct a possible crash in main GRIB dialog right click menu
Handle the case of plugin library without read permissions properly
Refine the AIS target track persistency implementation to allow saving the track for as long as the user decides.
Merge pull request #215 from Ptizef/master

Correct a possible crash in main GRIB dialog right click menu
Merge pull request #216 from nohal/pluginlibperms

Handle the case of plugin library without read permissions properly
Re-Correct rotated chart region calculation.
Merge pull request #217 from nohal/aistrkpers

Refine the AIS target track persistency implementation
Improve quilt mode toggle ("Q") responsiveness.
Avoid adding Garmin USB device to Connections list if not actually present.