Automatic dhcp_scope detection

Every network now can loosely have a 'dhcp_scope' value associated with
it. This is accomplished via first looking in the network's keyvalue
store for a 'dhcp_scope' key and if that key doesn't exist, calculate a
possible scope value by looking at the network's site/vlan.

During SREG creation the 'dhcp_scope' key will be set on any new
HWAdapters automatically. The value will be set to the dhcp_scope
value of the network of the range that is selected from the ip-chooser
widget.

DHCP scope key mismatches are highlighted in red.
Add self-service csv exporter
hack to fix broken import
Attempt to fix sporadic ise
catch ValueError to display better message
gaurd against no network
save! failing tests at mozdns/mozbind/tests/build_tests.py:test_too_many_config_lines_changed
nameservers trigger a rebuild
better logging and tweaked rebuild to look at specific zones when its not a clobber build
updates
comments and variable name changes. going to rebase eventually...
don't depend on gen_config to not add a zone to the config files