Some exceptions raise UnicodeError

Use utils.exception_to_str to consistently cast the
exception to avoid the unicodeError stack trace.

Closes-Bug: #1340002
Related-Id: I54fce91c73adca846ec99ed50a57b95d16428ec1

Change-Id: I77478a8eeeefd85bf98138156429df53d0a4c079
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Fix unsaved exception in v1 API controller

When an exception occurs during exception handling, it lose the
information of the first exception.

We should use the excutils.save_and_reraise_exception() in this case.

Change-Id: I467c9627fa661421926d50c3e894f80d9b75baa2
Signed-off-by: Zhi Yan Liu <zhiyanl@cn.ibm.com>
Merge "Some exceptions raise UnicodeError"
Merge "Fix unsaved exception in v1 API controller"