Rename Queue related methods for VMware NSX plugin

This is the first step of many for renaming/refactoring
nvplib and related modules. Starting with queues, whose
code is small and less daunting.

Partial-implements blueprint: nicira-plugin-renaming

Change-Id: I2db899883c61f30c8b15703c96290872e853d670
Use save_and_reraise_exception when reraise exception

This commit fixes neutron core and common codes.

Partial-Bug: #1279813
Change-Id: Id109924c7ff9b4f0d74c23665016a54bfd7dff77
Merge "Rename Queue related methods for VMware NSX plugin"
Add DB mappings with NSX logical routers

This patch introduces DB mappings between neutron and NSX router,
thus not requiring anymore the Neutron router ID to be equal to the
NSX one.

This change is needed for enabling asynchronous operations in
the NSX plugin.

This patch also performs NVP/NSX renaming where appropriate, and
fixes delete router logic causing a 500 HTTP error to be returned
when a Neutron internal error occurs.

Related to blueprint nvp-async-backend-communication
Related to blueprint nicira-plugin-renaming

Change-Id: Ib0e9ed0f58e7fa3497a93e9cd3baa9cb81ad797b