Fix API handler generator to support GET appropriately

This patch fixes the decorator for the API handler generator to add
methods correspond to HTTP GET for the single and multiple resources.

Change-Id: Ifffbb8f70390b9f543b0e267e681b86b9508432c
Signed-off-by: Taku Fukushima <tfukushima@midokura.com>
Add Tunnel Zone and Tunnel Zone Host API handlers

This patch adds TunnelzoneHandlerMixin and
TunnelzonehostHandlerMixin to the core plugin using
generate_methods decorators.

This patch also adds symbols for 'list', 'show', 'create', 'update'
and 'delete'. It'd be too easy to have typos for them and I added
symbols for them to make it easier to detect typos using the static
checker.

Change-Id: Ia652c5afa0e00a358325b80d6c6dab27152ced56
Signed-off-by: Taku Fukushima <tfukushima@midokura.com>
Add tunnelzone extension

This patch adds tunnelzone extension and unit tests for tunnelzone
extension.

Change-Id: I085977e56928003e0421b1f210386fec8731a493
Signed-off-by: Taku Fukushima <tfukushima@midokura.com>
Add methods required for the plugin

Change-Id: Ifca07bf17ac9c7e946101ff665f3aef310949e30
Signed-off-by: Taku Fukushima <tfukushima@midokura.com>