More experiments with jQuery DataTables.

Can't seem to get the tutorial to work, though.
Cleaning up main.py via dictionaries.

Also added a new variable in main_app.py, module_name.
Adding page_scripts to the template render of homepage.

However, a bug seems to be introduced when logging-in with empty credentials. We
are redirected to the dashboard page with matching status 500.
Kidding. This is where I introduce the module_name template variable.
Added comment docs to templates.