* Add a command to generate configuration examples
Config files are generated from templates (which remplace previous example files).
- solve the issue of hard-to-explain configuration examples
- ease pkg path seeking (avoid it, actually)
- add working defaults for sqlite and unix socket paths (instead of
/replace/me/path/example)
- move settings comments from default_settings.py to ihatemoney.cfg.j2, as it is
the one that will be facing user.
* Use generate-config command in install doc
Also follow the new working defaults of templates for socket and db path.
* Fix doc settings table
On the long term, plaintext tables might destroy humanity.
* Mention templates dir URL in documentation
As requested by @almet
