* Use std::sting instead of char[] in the graph drawing functions. This is the
only change to the code. Rest is just styling.
* Corrected whole code to follow Allman/GNU coding style, with 2 spaces for each
indentation step.
* Added license headers to all code files
* Added vim modelines to all files. They sit on the first line and enable the
following settings: 2 space indentation, tab expansion to spaces, line at
80th column, automatic line breaking on "\ !@*+-;:,./?" characters, automatic
line break if line exceeds 80 colums. This should keep the code nice and tidy.