webadmin: Showing more than one canDoMessage for action in multiple action

If an action that is part of muliple action has more than one canDoMessage,
just the first message is displayed.
This patch fixes it.

Also, if the action has description, it should also be displayed.

Change-Id: I89338d119144279d84c08b62543e836c3492f07e
Bug-Url: https://bugzilla.redhat.com/878451
Signed-off-by: Alona Kaplan <alkaplan@redhat.com>
engine: Extended error for pinned host missing non required network

There are a lot of reasons for a vm pinned to a host to fail running.
The old message specified just a small amount of them.

The message was fixed to display the exact reason for which the vm failed
to run.

Change-Id: Ibf9703ae06b06be96c6508d48306d8bd6b8bcfbb
Bug-Url: https://bugzilla.redhat.com/878451
Signed-off-by: Alona Kaplan <alkaplan@redhat.com>