add GET /{tenant_id}/stacks/detail to Heat API

Enables the building of a useful dashboard interface for Heat stacks
without looping through stacks returned from "/{tenant_id}/stacks/"
to fetch the detailed data.

Fixes bug #1191117

Change-Id: I06b1100873de462c69302e43259df13104cad79f
Fixup handle_create backup restore.

The handle_create did not retrieve the volume_id
correctly and the check_create_complete
needs to handle the restoring-backup status.

Also modify and add support for restoring-backup
status test cases for success and error.
The additional FakeVolumeFromBackup will force
the inital status to be checked by the method
check_create_complete in volume.py.

Fix bug 1195403.

Change-Id: I60bf4f9f90be1058d0fb400aa3778d0448b1a898
install "_" via gettextutils

avoid using two separate sets of translation messages when
HEAT_LOCALEDIR environment variable presents.

Fixes bug #1196184

Change-Id: Ief773b9f2674909de461e2b07f1b07d3c66521cc
Merge "add GET /{tenant_id}/stacks/detail to Heat API"
Merge "install "_" via gettextutils"
Merge "Fixup handle_create backup restore."