It is useful to log the request as it is being made to the
server rather than relying entirely on logging generated
after the request. Logging before the request is processed can
help a person debugging with understanding when the client
first made the request.
Log the client's user agent string.

Signed-off-by: John Mulligan <[email protected]>

Support having the rest client library send a more specific
user agent string to the server. Provide a mechanism for
tools built upon that library to add more specific user agent
information.
Use the api in the glusercli command line tool to specify
itself.

Signed-off-by: John Mulligan <[email protected]>

Extend the cli such that it can send it's original command line
arguments to the server so that the server may log the
original command that initiated the api call.

Signed-off-by: John Mulligan <[email protected]>