Add snapshot related data to limits api

When calling the limits api we can only get Volume and Gigabyte data,
the snapshot related limit value should be returned too.

Change-Id: I6a5e1e2d1aa6abbac5d5dacd042223ce49207c1f
Closes-bug: 1282924
Use six.moves.urllib.parse instead of urlparse

To keep Python 3.x compatibility, use six.moves.urllib.parse to
replace urlparse. tools/lintstack is changed to pass pylint test.

Partial-Bug: #1279611

Change-Id: I0ceaaccbf6c67b45609b4f2f5639c362b32d10ad
Merge "Add snapshot related data to limits api"
Merge "Use six.moves.urllib.parse instead of urlparse"