Add conditions in compute APIRouter

The Route of versions should add HTTP GET methods conditions, because
it only has a 'show' action, thus other methods will not match.

Fixes bug 1088530

Change-Id: Ib21381324cf7067015d0a6e36a0f0292eb902fe9
improve libguestfs exception handling

* nova/virt/disk/vfs/guestfs.py (teardown): Handle specific
exceptions when tearing down so that (future) nova bugs
aren't masked.  Also handle AttributeError so that the
relatively new handle() and close() don't cause erroneous
debug logs on older versions of libguestfs.
(has_file): remove the last use of generic exception
catching and use the more specific RuntimeError.

Change-Id: Ia7345675d75c1c6727e9254791d44475c0ed9295
Adding two snapshot related task states

The first, 'image_pending_upload', indicates that the snapshot of a given
instance has been taken and it is being prepared for uploading to the
image service.

The second, 'image_uploading', indicates that the compute manager has
initiated upload to the image service.

Implements blueprint snapshot-task-states

Change-Id: I256c5d21a1d23b87d2060cca99eb9839c5b89161
Imported Translations from Transifex

Change-Id: I3037df2c2e65c6de170700d766a75e025cbfa9f3
Merge "Adding two snapshot related task states"
Merge "improve libguestfs exception handling"
Merge "Add conditions in compute APIRouter"
Merge "Imported Translations from Transifex"