Ensure DB pooling code works with newer eventlet versions

Bug 1097992

Change-Id: Id14697a0a4815d0aacbae769bf538a96d6846567
Update latest OSLO

Includes fix for bug 1158179

Change-Id: Ifd8cde2903dcd013903e95a30c2ed422e89bcd0f
Merge "Update latest OSLO"
Adjust exception message in l3 agent

Bug 1159856

Change-Id: I8d30fd50d46677fc112fe4d8406b849cbb8ef225
Merge "Ensure DB pooling code works with newer eventlet versions"