allow adding more navigation items after a theme was loaded
recovered "sites" initializer from old crabgrass repository
enabled site "site1" in development config, to be able to work with superadmin
added Crabgrass.mod_routes to add routes from mods before the catchall route
fix alphabetized group list sql
refactor theme loading
app/common/views doees not exist - no use as view path
don't set banner to group just because @group is set

In superadmin we edit and create groups but want to keep the admin banner.
.present? is only available once ActiveSupport is loaded

using chars.any? instead since the constant is defined for sure
alphabetized without order

superadmin uses alphabetized with a different order. Also the alphabetical_order is not related to login but to display_name || login
minor: comment fixed to refer to castle_gates
use acts_as_extensible instead of include hack for mods
use ActiveSupport Concerns to extend controllers.
reset navigation when reloading

This way we are reloading the bare theme without modifications. So they need to be applied again.
Merge pull request #96 from Crabgrass/feature/mod-requirements

Feature/mod requirements
Merge pull request #95 from Crabgrass/feature/extendable_themes

allow adding more navigation items after a theme was loaded
directory is not available in #load - log initializer instead