Adds new function 'showAddNetwork' to instance wizard configuration,
which conditionally hides the 'add network form' on the select network
step. If it returns true, then show the box, otherwise false hides it.
Adds drop-down select to filter networks by VPC.
-If no VPC is selected, only show non-VPC isolated networks
-If VPC is selected, show tiers from specified VPC. Note that only one
tier/network can be checked at a time in this mode, and 'add network'
text field is hidden
** Note: this is a work-in-progress, and only contains dummy content
Implement UI for managing VPC tiers, via a custom chart-like UI list
tiers and allowing the management of VMs associated with the VPCs.
