Added simple initscript from debian-wheezy-like Linux distros

This is a fairly simple script, and of course is meant to be basicly customized  by the user who is installing err.

Basically, what is meant to be customized is:

* The `CONFIG_DIR` variable
* The `ERR` variable, in order to point to the err.py script
* The `BACKEND` variable, to choose the backend.

Hope this helps.