Fix locking in rpc_get_methods().
Fix locking in rpc_get_methods().

API change: com.twoporeguys.librpc.Introspectable.get_methods call is not
streaming anymore.

twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc,twoporeguys/librpc