Improve StackUp/Down chart selection logic.
Correct cm93 regression memory fault.
Correct fault drawing complex chart information objects (FS#1380)
Merge branch 'master' of https://github.com/OpenCPN/OpenCPN into mainline

Conflicts:
	include/chart1.h
	src/chart1.cpp
	src/cm93.cpp
	src/s52plib.cpp