hosts mulitple

fixes #2001 - Changing Loc or Org after compute resource selection give 500 error

fixes #1999 - Allow org/location to selectively ignore a domain, subnet etc

TODO: excluding views

refactor - move clone taxonomy to models

fixes #2138 - Ensure at least one Location / Organization exists

fixes #2126 Large report messages won't fit in PostgreSQL's index_messages_on_value

fix import classes button

lighter style to the host status labels.

Make sure we're not merging nil in to_json

Options argument might be nil. Therefore it fails when trying to call {}.merge(options) (for example when recording examples with apipie).

fixes #2147 - param classes with multiple matchers are evaluated incorrectly