Adds exception handling around heat stack creation

Reasons:
- heat_client.stacks.create raises HTTPException which was not
  captured in heat work-flow.

Changes:
- Adds heat_exceptions.HTTPException in the exceptions captured
  while stack creation.

Change-Id: Ia87e1f6d08ac062e1085dd1c0b0c4197a74597d4
Closes-Bug: #1325049
Add warnings when a path for api_extensions_path does not exist

This commit fixes api-paste factory to show warnings when the path
for api_extensions_path doesn't exist.

Change-Id: I2288e39d6740aabc7818c3c963257e700237afe5
Closes-Bug: #1301660
Add slave_of_id to instance model

Add new 'slave_of_id' field to instance model and schema.

partially implements blueprint replication-v1
Change-Id: I613eaed6057745f38ffffafad2c72a0338b2552a
Delete undeclared variable in guest-agent API class

The commit c7d93e7ce74c20a9c59ee0d2d542ed5b54d9c39c (not linked to
a gerrit review) introduced a local variable "timeout", used in a
 method of the API class

The review I9ad1b441eca855a4304454014ae746ec51bef8f3 deleted the
declaration of this variable but did not remove where it was used
in the class.

This patch removes the unused variable.

Closes-Bug: #1332333
Change-Id: Ie7aa66ceeca4efe63d91d60bcedb760ec181d443
Imported Translations from Transifex

Change-Id: Id76b9c033eadef8be7a8538430089d6dd434fd0b
Merge "Add slave_of_id to instance model"
Merge "Add warnings when a path for api_extensions_path does not exist"
Merge "Adds exception handling around heat stack creation"
Imported Translations from Transifex

Change-Id: Ib81179ee7494e45983af0b0b98b1ea9756378f6e
Merge "Delete undeclared variable in guest-agent API class"