Separate config and automatically find root path

[maltoe]

Hi Stefan,

this adds automatic root path resolution. I wanted to symlink the script to my local bin directory instead of modifying PATH. Could have set the environment variable instead, but I figured it would be nice if the script would autolocate its data.

The second patch separates the configuration (i.e. the colorscheme file :) from the code, storing it at XDG_CONFIG_HOME or below HOME, if the former is not available.

Cheers malte