Pika library updated
fix database connection problem

when fetching attribute from database you need to call db.close()
and db.closeSession() to really close both the connection and the
session used by sqlalchemy, if you forget to call closeSession
the session connection will be kept alive and after some hours might
be closed by mysql.

Removed a lot of cut&paste code to fetch various attributes and created
a common function, which should be used everywhere in the code
commands: remove non ASCI characters
imgstorage: use the new imgstorage.get_attribute in vm daemon

now imgstorage.imgstoragevm also uses the new function
imgstorage.get_attribute to fetch attributes
imgstorage: fix a missing import in imgstoragevm
imgstorage: fix typo in imgstoragenas
rocks-command: cleanup of the node now works automatically from FE

with this patch rocks clean host storagemap can now be run from the
FE and then it will take care to ssh to the nodes and do the cleanup
imgstorage: call get_blk_dev_list only if it is really necessary

unmap_zvol was making a call to get_blk_dev_list which was not necessary
imgstorage: fix some code indentation
imgstorage: log when daemon start
imgstorage: check before unmapping block device device

sometimes when unmapping the a volume the VM is still holding
the block device by the time imgstorage tries to unmap it and
it gets this error;

Error: Error detaching iSCSI target from compute node: Error executing dmsetup: device-mapper: remove ioctl on vm-rocks-153-1-vol-snap failed: Device or resource busy

To avoid this problem it now performs a check to verify the device
is free before destroing it

TODO: it should re-queue the request instead of sleeping