add 'force' verification in _volume_upload_image

_volume_upload_image API should only support to upload 'in-use' volume to
image when assign 'force' parameter as true value. Now
_volume_upload_image API does not do verification for 'force' parameter,
so we can upload 'in-use' volume to image when assign 'force' parameter
with string value 'false' or 'false111'. This patch add verification for
'force' parameter.

Change-Id: I9e1d0e517d0ff97c136903dd6e50a305e18651f3
Closes-Bug: #1265718
removed unused context in check_*** methods

Input parameter 'context' of Check_*** methods(check_attach,
check_detach, _check_metadata_properties, _check_volume_availability)
in cinder/volume/api.py are not being used, so remove this 'context'
parameter.

Change-Id: I314f662f2fe54a6b073181ff5c0f0214e9ef822a
Closes-bug: #1265725
LVM: Fix "intialized" typo in warning msg

Change-Id: I3b07b30840835a46c165fc360522b268229f5e50
Merge "LVM: Fix "intialized" typo in warning msg"
Merge "add 'force' verification in _volume_upload_image"
Merge "removed unused context in check_*** methods"