Update database.rst

i kept trying to import the .gz mbox files, and i was going crazy, then on a whim i tried the .txt ones and that worked!
Redesign of the list overview page, including extensive modification of the graph and a lot of CSS tweaks
Merge branch 'master' of github.com:mairin/hyperkitty
forgot to commit a filter needed for the list overview changes
converting header from overview from h2 to h1 for more consistency across pages
adjusted category badges on list overview; fixed > in breadcrumb
Merge branch 'master' of ssh://github.com/mairin/hyperkitty into plugin-api-mairin

Conflicts:
	hyperkitty/templates/overview.html