Avoid using GREENDNS due to dnspython

If dnspython is present in your environment then
eventlet monkeypatches socket.getaddrinfo() with an implementation
which doesn't work for IPv6. To turn this off you need to set an
environment variable before you do the import.

Resolves bug 1164822

Change-Id: I4aa3d40d0f8d0f125c3a89c4ba062ad0d13f1c55
Set useful vendor/product id in Cinder ISCSI exports

This can be very useful for debugging and can be used
to filter out access from tenant volumes within compute
hosts.

Change-Id: Ib7ddb824043536a92024ada30476d00fd171e800
Robustify skipactivation detection

When lvchange is not in the $PATH for non-root user,
this code otherwise traces.

Change-Id: I308bd97cb729e83677f18a693274265a182d794c
Closes-Bug: #1269445
Deactivate LV before removing

With certain versions of LVM2, removing an active LV can end up with

  Unable to deactivate open XXX
  libdevmapper exiting with 1 device(s) still suspended.

which causes any lvm command afterwards to hang endlessly on
trying to access the suspended volume. This seems to be caused
by a race with udev, so lets be conservative and do the deactivation,
then wait for udev and then finish the removal.

Closes-Bug: #1270192

Change-Id: I4703133180567090878ea5047dd29d9f97ad85ab
Import glance_api_version from cinder.common.config

Fixes bug 1290883

Change-Id: I9f64c2f60efe517ad8e4ee2a98ed8da4be257b47
Remove explicit dependency on amqplib

amqp (or amqplib) is only accessed via kombu, and kombu
already specifies the right dependency (either amqp if new
enough or amqplib for old versions of kombu).

Change-Id: I4efa419db1befdfcbe639a8557e21eb97ca3a26e
Cinder override all() method
Add _wrap_db_error support for postgresql

The original "_wrap_db_error" function is only available for mysql.
We need to add support for postgresql.