Snapshot failure with non-ASCII name in RHEV 3.0

Issue

• Attempting to create a snapshot whose name contains any non-ASCII characters fails
• vdsm.log shows an error similar to:

Thread-1869657::ERROR::2013-12-15 20:32:28,855::misc::66::irs::'ascii' codec can't encode characters in position 798-
799: ordinal not in range(128)
Thread-1869657::ERROR::2013-12-15 20:32:28,857::misc::67::irs::Traceback (most recent call last):
  File "/usr/share/vdsm/storage/task.py", line 978, in _run
  File "/usr/share/vdsm/storage/spm.py", line 107, in run
  File "/usr/share/vdsm/storage/spm.py", line 1123, in public_updateVM
  File "/usr/share/vdsm/storage/sp.py", line 1089, in updateVM
UnicodeEncodeError: 'ascii' codec can't encode characters in position 798-799: ordinal not in range(128)