New config parameter STORAGE_BASE

- allow configuration of a "base" under which the output files will be placed
- OUTDIR will be relative to STORAGE_BASE
- by default, STORAGE_BASE is empty ("backwards compatible :)")
Enriching sample config with some comments

- should make it easier for the user to edit his/her copy without reading all the docs
More control to the user via config

- all parts of generated scripts can now be disabled via config file