Change v3 agents API to v2.1

This patch changes v3 agents API to v2.1 and makes v2 unit tests
share between v2 and v2.1.

The differences between v2 and v3 are described on the wiki page
https://wiki.openstack.org/wiki/NovaAPIv2tov3 .

Partially implements blueprint v2-on-v3-api

Change-Id: I96dd9cd3672c6d584bd0019c385544c08f687e7f
Change V3 access_ips extension into v2.1

This patch changes v3 access_ips API to v2.1 and makes v2
unit tests share between v2 and v2.1.
The differences between v2 and v3 are described on the wiki page
https://wiki.openstack.org/wiki/NovaAPIv2tov3 .

Partially implements blueprint v2-on-v3-api

Change-Id: Id464cbe4a8b7a7749c4f14e4531e4494dd315857
Refactor admin_action plugin and test cases

use common.get_instance()instead of self.compute_api.get()
add expected_attrs=None when setup mock in test case.

this patches is aimed to share v2.1 patches and v2 test cases.
a test cases porting patch will be followed.

Partially implements blueprint v2-on-v3-api
Change-Id: Iea7b0c0c2c920108ef055681319d8a2d996e14b3
VMware: add resource limits for CPU

The flavor extra specs for quotas has been extended to support
 quota:cpu_limit - upper bound of CPU allocation (MHz)
 quota:cpu_reservation -  guaranteed minimum CPU allocation (MHz)

This enables the VMware driver to provide enable CPU allocations
for the running instance.

DocImpact

Change-Id: I1bec4f009285f7991eaaa8155329366a4eba5e1f
VMware: Add in support for CPU shares in event of resource contention

The flavor extra specs for quotas has been extended to support
 quota:cpu_shares_level - the allocation level. This can be 'custom', 'high'
                          'normal' or 'low'.
 quota:cpu_shares_share - in the event that 'custom' is used, this is the
                          number of shares.

This enables the VMware driver to provide CPU shares.

DocImpact

Change-Id: Iba55f91a5374ec6a1412e726a7ae2fbf2641155b
Merge "VMware: add resource limits for CPU"
Merge "VMware: Add in support for CPU shares in event of resource contention"
Merge "Change v3 agents API to v2.1"
Merge "Refactor admin_action plugin and test cases"
Merge "Change V3 access_ips extension into v2.1"