Glance v2: Include image/member id in 404 Response

Fixes bug 1242920

Change-Id: Idfce3026073be036f0c2416d33065741a342abfd
Add unit test cases for get func of db member repo

Fixes bug 1232756

Change-Id: I35a2cca7108d0a178d33a15594a2b8d56961ab73
Merge "Glance v2: Include image/member id in 404 Response"
Merge "Add unit test cases for get func of db member repo"