fixup opengl extensions, support fbo without texture rectangle, correctly compress etc data when not cached
improve logic to help inefficient toolbar
greatly improve vector chart rendering efficiency by using a texture for the chart symbols
Merge coron:build/OpenCPN into optimum

Conflicts:
	src/glChartCanvas.cpp
fix a problem where zero sized patterns cause an endless loop
remove long unused code
improve arc rendering especially for opengles
fix npot support on opengles
Merge cubian:build/OpenCPN into optimum