fixes #5939: it's no longer possible to switch tabs when compute profile is being edited.
fixes #6355 - OS free text search shouldn't search associations
fixes #6374 - NIC hostname now blank when domain is present, but no hostname is given
Fixes #6337 - ensure VM tab is still visible when we deselect profile
[REFACTOR] refs #6229 - extract validation to a method

this enables plugins (e.g. katello) to override the validation when
requried.
fixes #6319 - precompile dashboard.js
fixes #6382 - revert name change of 48bit mac address regex to fix discovery
fixes #6410 - update to deep_cloneable 2.0
fixes #6400 - show * next to required fields on forms
fixes #6226 - if only one option for required field on new host page (ex. installation media), then automatically select it
fixes #6401 - change include blank option to 'No environments' or 'No subnets', etc if there are no select options
              change include blank option to 'Select environment' or 'Select subnet' if required field and more than one option