Correct GRIB OVerlay y-axis orientation.
X11FontPicker (probably obsolete) moved into platform specific subdirectory.
Created namespace/subdir 'graphics' to break up cyclic dependencies.
Moved default start position to where it belongs.
Resolved compiler warnings.
Refactoring: wx array replaced with std::vector
Refactoring: moved some files to the 'graphics' package.
fix: compiler warnings about order of initialization
Resolved some issues found by cppcheck.
bug fix: windows build
Merge branch 'master' of https://github.com/OpenCPN/OpenCPN into mainline