Description of configuration options for meta

Configuration option = Default value	Description
[META]
default_flavor =	(StrOpt) Default flavor to use
default_l3_flavor =	(StrOpt) Default L3 flavor to use
extension_map =	(StrOpt) A list of extensions, per plugin, to load.
l3_plugin_list =	(StrOpt) List of L3 plugins to load
plugin_list =	(StrOpt) List of plugins to load
rpc_flavor =	(StrOpt) Flavor of which plugin handles RPC
supported_extension_aliases =	(StrOpt) Supported extension aliases