Rename: VALUES to ALLOWED_VALUES, PATTERN to ALLOWED_PATTERN

Rename VALUES to ALLOWED_VALUES, PATTERN to ALLOWED_PATTERN in
parameters and modify related references in other modules

Implements blueprint hot-parameters

Change-Id: Iad018f6a9fc1166aa2c5d94720faf997dc7e98a3
Change token name from context.

Remove password auth from pyrax to conform with
the changes going through the engine regarding
not using a password. Previous commit was an
incorrect branch with a bug.

blueprint pyrax-token-auth

Change-Id: I47cd00199133b88a2343b12c847635c726452629
Merge "Change token name from context."
Merge "Rename: VALUES to ALLOWED_VALUES, PATTERN to ALLOWED_PATTERN"