Update to readme, better markup.
Merge pull request #9 from PetterS/linux

Fixed linux compile warnings in cppmatrix.h and updated the readme with compile instructions.
Merge pull request #10 from PetterS/dev

* Visit map functionality added with example.
* Simple Matlab 3D example.
and small changed to the Matlab interface and code.
Windows fig. Matlab cannot display colormaps of more than 256 colros in windows without openGL this is a fix.