api: Add an API to retrieve application configuration

To keep the UI and backend decoupled, we need an API for the UI to
access elements of the server configuration.  The first user of this
will be to allow an HTTPS instance of the server to redirect to the HTTP
instance (for VNC connections).  In the future we can extend this to
support capabilities reporting as well.

Signed-off-by: Adam Litke <agl@linux.vnet.ibm.com>
server: Support SSL connections
tests: Test the REST API using an SSL connection

Now that we have SSL support in the server, let's make sure to test it.
This patch makes some changes to the test utils so that SSL requests can
be done transparently.  Now test_rest runs through all tests twice: once
over http and a second time over https.

Signed-off-by: Adam Litke <agl@linux.vnet.ibm.com>