Rename Neutron core/service plugins for VMware NSX

Short aliases are introduced for the NSX plugin(s). This patch
also switches to using the new plugin names/naming scheme in
the unit tests.

Partial-implements blueprint: nicira-plugin-renaming

Change-Id: If1f1431b098bf77b9c85e0afb3d7848083d9d451
Replace binding:capabilities with binding:vif_details

In addition to binding:vif_type, the neutron core plugin needs to
supply various information to nova's VIF driver, such as VIF security
details and PCI details when SR-IOV is being used. This information is
read-only, requires admin privileges, and is not intended for normal
users. Rather than add separate mechanisms throughout the stack for
each such requirement, the binding:capabilities port attibute, which
is a dictionary and is not currently not used by nova, is renamed to
binding:vif_details to serve as a general-purpose mechanism for
supplying binding-specific details to the VIF driver.

This patch does not remove or replace the CAP_PORT_FILTER boolean
previously used in binding:capabilities. A separate patch should
implement the specific key/value pairs carried by binding:vif_details
to implement VIF security. Another patch will implement the key/value
pairs needed for SR-IOV.

The ML2 plugin now allows the bound mechanism driver to supply the
binding:vif_details dictionary content, instead of just the
CAP_PORT_FILTER boolean previously carried by the binding:capabilities
attribute.

DocImpact: Need to update portbinding extension API, but no impact on
user or administrator documentation.

Implements: blueprint vif-details
Related-Bug: 1112912
Change-Id: I34be746fcfa73c70f72b4f9add8eff3ac88c723f
options: consolidate options definitions

Some config options(interface_driver, use_namespaces) are defined
multiple times in ad-hoc way.  It causes DuplicateOptError exception
when using those module at the same time.  Right now the exception is
avoided in ad-hoc way by each executable.  Those duplicated
definitions should be consolidated and treated in uniformed way.

This is the blocker for blueprint: l3-agent-consolidation

neutron.services.loadbalancer.drivers.haproxy.agent periodic_interval
conflicts with neutron.service one. Since there is no way to fix it
without changing existing behavior/default value, it is untouched for now.

Closes-bug: #1279769
Change-Id: Ifed79b7ee0033644854499416f8a2b22a20416fe
Merge "Replace binding:capabilities with binding:vif_details"
Merge "options: consolidate options definitions"
Merge "Rename Neutron core/service plugins for VMware NSX"