Great refactoring and some bug fixes

I'm really sorry that this commit is rather radical, but there were so many things that could have been done better.
For next contributors:
This site http://mywiki.wooledge.org/BashGuide has all needed info about writing code in bash. Most of the time you don't have to use any external tools, bash can handle pretty much everything. For example instead of 

    echo "$var" | tr [a-z] [A-Z]
you can use

    echo "${var^^}"

This does not call any external tool, does not create any new process and definitely works faster. That's just one example. For more hacky stuff read about [bash parameter expansion](http://wiki.bash-hackers.org/syntax/pe)
Another popular problem is about [correct parameter quoting](http://mywiki.wooledge.org/WordSplitting). 

There are several other things I'd like to change here, for example text formatting of install files could be done automatically. But it's already too much for now.

Not all of crunchbang scripts are currently on github. Could you be so kind to upload the remaining part?

Thanks for this great distribution! Please keep up the work!