Fixes error message encoding issue when using qpid

Making the message only consist of primitive types
before sending it by qpid.

Fixes bug 1242734

Change-Id: I3ff7a19af9a7671f955345ada6acfba8bf573c70
Document default log location in config files

It's not immediately obvious where log output will go if the 'log_file' and
'use_syslog' directives are either missing or commented out.  This patch updates
the documentation in the config files to mention the stdout default.  This
should help remove any confusion when configuring logging for glance.

Change-Id: I36f2a9d30bdee1949e60f413b7f181631c564ed5
Closes-Bug: #1248292
Merge "Document default log location in config files"
Merge "Fixes error message encoding issue when using qpid"