'Configure from a configuration dictionary
and a prefix.
Example::
local_region = make_region()
memcached_region = make_region()
# regions are ready to use for function
# decorators, but not yet for actual caching
# later, when config is available
myconfig = {
"cache.local.backend":"dogpile.cache.dbm",
"cache.local.arguments.filename":"/path/to/dbmfile.dbm",
"cache.memcached.backend":"dogpile.cache.pylibmc",
"cache.memcached.arguments.url":"127.0.0.1, 10.0.0.1",
local_region.configure_from_config(myconfig, "cache.local.")
memcached_region.configure_from_config(myconfig,
"cache.memcached.")'

def configure_from_config(self, config_dict, prefix):

    config_dict = coerce_string_conf(config_dict)
    return self.configure(config_dict[('%sbackend' % prefix)], expiration_time=config_dict.get(('%sexpiration_time' % prefix), None), _config_argument_dict=config_dict, _config_prefix=('%sarguments.' % prefix), wrap=config_dict.get(('%swrap' % prefix), None))
