add texture based font rendering support
Improve StackUp/Down chart selection logic.
Correct cm93 regression memory fault.
Correct fault drawing complex chart information objects (FS#1380)
Merge branch 'sean_optimum' into my_merge
Merge branch 'master' of https://github.com/OpenCPN/OpenCPN into optimum

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