Encode error messages before sending them to stdout

When an error with non-ascii characters is caught by glanceclient, it
fails at printing it and exists with a UnicodeEncodedError. This patch
encodes errors' messages using strutils before sending them to stdout.

Fixes bug: #1200206

Change-Id: I4dabcd76ffb258840bd6a66ad23c030f34960e86

glanceclient/shell.py

@@ -472,5 +472,5 @@ def main():
         print >> sys.stderr, '... terminating glance client'
         sys.exit(1)
     except Exception as e:
-        print >> sys.stderr, e
+        print >> sys.stderr, utils.exception_to_str(e)
         sys.exit(1)