The coordinates.DEFAULT_MAP_SETTINGS hadn't been used anymore since
1.64 (april 2011), removed it.

coordinates.DEFAULT_OSM_MAP_LAYER was used in views.py, for the case where
there were no background maps defined. Moved this setting and the code
to get the default maps into models.BackgroundMap, where they belong.
Slightly refactor has_google method
Add simple test for default_maps()
Remove unused import
Fix typo
Move settings and their defaults to conf.py (using django-appconf).

The Setting model's .get() and .extent() functions now don't take a
default anymore, rather if a Setting isn't found they get their
defaults from normal Django settings -- a setting called "mysetting"
uses the LIZARD_MAP_DEFAULT_MYSETTING_SETTING setting. Setting setting
setting.

Several defaults were updated to what lizard5-site sets in its
base.py, so the settings can be removed there. No other settings were
actually set in lizard5-site, so how configurable do these things need
to be?
Fix bootstrap_tour Setting
Actually make Setting work, add tests
Make other tests work with the current code
Fix other tests
Merge pull request #38 from lizardsystem/remco-figure-out-settings

Remco figure out settings