Fix wrong key for 'usage.summary.instances' in CSV summary

In the project overview, the key for 'usage.summary.instances' the CSV
summary is wrong, it should be "Active Instances" instead of "Total
Active VCPUs".

Change-Id: Idf09fee592d522b7ebf5cffd0ce31240407c59d0
Closes-bug: 1288020
Improve help message in Retrieve Password form

A private key is used to decrypt a password.
It is better to update the message to mention "private key" explicitly
instead of "key pair". "key pair" is a pair of private and public key.

Change-Id: Icd5aa8fae2a348df011861469d028903bd71ec02
Closes-Bug: #1291529
Clarified success message for instance resize

Resize is an asynchronous action; the success
message can only confirm that the request for
resize was accepted by the nova API service
and that a corresponding RPC message was sent
to the nova scheduler service.

Closes-Bug: #1277257
Change-Id: I125c79c4c76fcb27f1e0d3c7122125e9036b1008
Merge "Improve help message in Retrieve Password form"
Merge "Clarified success message for instance resize"
Merge "Fix wrong key for 'usage.summary.instances' in CSV summary"