Simple Subnets: disable presence validation for gateway

fixes BZ #1153116
Merge pull request #350 from ifarkas/simple_subnets-delete_gateway_presence_validation

Simple Subnets: disable presence validation for gateway
Fixes BZ#1152655 - increases width of All Details modal and spacing
Merge pull request #351 from knowncitizen/bz1152655

Fixes BZ#1152655 - increases width of All Details modal and spacing
Version 0.4.6
BZ #1151603: Change interface filter to look at non-VIP interfaces

https://bugzilla.redhat.com/show_bug.cgi?id=1151603

The interface assignment screen was supposed to filter out already
assigned, non-vip subnets. It was changed to 'vip' in a refactor. What
then happened is that the subnet where the vips were assigned would get
filtered out, and could no longer be assigned to an interface.
Merge pull request #353 from bcrochet/bz/1151603

BZ #1151603: Change interface filter to look at non-VIP interfaces
BZ #1154669: Allow host to be set to existing hostgroup

https://bugzilla.redhat.com/show_bug.cgi?id=1154669

If the host is already associated to a deployment, this allows the host
to be edited directly in foreman, and to keep the hostgroup the same. It
will not allow any other deployment hostgroups.
Fixes bz#1146252 Redirect via window location if interfaces don't match
Merge pull request #355 from knowncitizen/bz1146252

Fixes bz#1146252 Redirect via window location if interfaces don't match
Merge pull request #354 from bcrochet/bz/1154669

BZ #1154669: Allow host to be set to existing hostgroup
Fix version specific deface erb tag

fixes BZ #1154745
Merge pull request #356 from ifarkas/fix_deface_erb_tag

Fix version specific deface erb tag
Adding architecture overview document
BZ #1154785: Ensure Public API subnet has a default gateway

https://bugzilla.redhat.com/show_bug.cgi?id=1154785

The public API subnet must have a default gw set. This ensures that
the public API type cannot be assigned to a subnet with the defgw.
Merge pull request #358 from bcrochet/bz/1154785

BZ #1154785: Ensure Public API subnet has a default gateway
Display subnet type on the primary interface and on new NIC form

partially fixes BZ #1154745
BZ #1151606: Do not destroy VIPs when assigning interfaces

https://bugzilla.redhat.com/show_bug.cgi?id=1151606

When interfaces are being assigned to subnets, Staypuft was destroying
the VIPs. And they would not get re-created. This keeps them from being
destroyed when a subnet with VIPs is moved around.
Merge pull request #360 from bcrochet/bz/1151606

BZ #1151606: Do not destroy VIPs when assigning interfaces
Fix edit override when no hostgroup is currently selected

When a host doesn't have a hostgroup already selected, the edit override
for the openstack hostgroups throws an error.