Update expression parser to MuParser muparser.beltoforion.de
Change to out of branch build system, and cmake include directory
added additional settings
added history pulldown menu
Added result formatting
Explained how to install perl dependencies, added functions, moved functions to subdir
moved excel and perl functions
Added function button to OpenCPN toolbar, with option to disable from settings
Cleanup of comments and debugging
Updated behaviour of history pulldown, respecting maximum
added ans variable
removed unused icon
typecast to int to make compiler happy
misc clean up