Add error handling to _connect function in PureISCSIDriver

The driver was throwing an exception when trying to connect a volume
to a host when they were already connected.  This change catches the
exception and looks up the existing connection information to use as
a return value.

Change-Id: Id0e6b1d3c3cd1e51745e97f99eef88a15e285526
Closes-Bug:  1403631
Fix format errors in brick/iscsi LOG messages

Currently in cinder.brick.iscsi.iscs:LioADM.create_iscsi_target
The Log message for the exception is:
  LOG.error("%s" % e),

This rightfully results in:
  *** UnicodeError: UnicodeError(u'Message objects
      do not support str() because they may contain
      non-ascii characters. Please use unicode() or
      translate() instead.',)

In some cases this causes the Volume service to stop and
doesn't help a ton with debug. While looking at this also
noticed a number of other similar cases where invalid LOG
messages were set up.  Following the i8n guidelines here:
http://docs.openstack.org/developer/oslo.i18n/guidelines.html

Went ahead and cleaned the bulk of the LOG messages in this
file up to adhere to the guidelines as well as fixing the
UnicodeError described in the bug.

Change-Id: I33adf99ca25a2d8f869de5bfa85b4ca8429be05e
Merge "Add error handling to _connect function in PureISCSIDriver"