Instance details view shows hostname (if it has it) or IP

Currently the hostname and IP is controlled by two config values:
trove_dns_support and add_addresses. I dont see a point of having
the hostname and IP indenpendent. It causes issues for old instances
when DNS is enabled.

I propose to simplify the view by showing hostname if it is set or
show the IP if it is not set.

Closes-bug: #1260567

Change-Id: Ia1fd47cbee89b10d53b0821e104a34eb31543846
Added Redis Crud Operations

blueprint redis-support

Change-Id: I741b3a39e1ec24ee81d441788be72f72726eda10
Remove copyright from empty files

According to policy change in HACKING:
http://docs.openstack.org/developer/hacking/#openstack-licensing
empty files should no longer contain copyright notices.

Change-Id: I3992a72c3614e2d0c65aee91e69d89ff806824fc
Closes-Bug: #1262424
Spelling correction in taskmanager/models.py

Changes:
-Corrected the definition spelling.

Change-Id: I8b3560ed9fb6b8cfaee0abe43df6500ac8f11027
Closes-Bug: #1270113
Edits on help strings

Fixes include rework of text, missing or extra spaces, wrong
capitalization and no sentence style capitalization.

Change-Id: If3d981d1736583b38328eeca5cc392fe10a7a0d0
Datastores improvements

List of improvements:
- added default_version field in datastore show output
- admin can list deactivated versions too
- admin can see extanded info about datastore version (image_id, packages)
- add possibility to retrive version by uuid (without specified datastore)

Implements: blueprint datastore-type-version-followon

Change-Id: I9b0c3547fb6a881a01db9e6e3d8d72077bc5ee29
Merge "Datastores improvements"
Merge "Remove copyright from empty files"
Merge "Added Redis Crud Operations"
Merge "Instance details view shows hostname (if it has it) or IP"
Merge "Edits on help strings"
Merge "Spelling correction in taskmanager/models.py"
Initial support for single instance Cassandra Database

Reasons
- This code adds ability to create/delete instance
with mongodb service type. No other operations supported.
- Trove should support multiple extensions. One of the is NoSQL support.
Main goal is to add support for Apache Cassandra NoSQL database.

Changes
This code gives ability to create/delete instance
with cassandra datastire type. No other operations supported.

Change-Id: Ib48f6392765af49c2df1447c3df46675825d210f
Implements: blueprint cassandra-db-support