JsonDbActor: added the main JSON database class
String: added reference() to allocate static strings from the stack
Receiver: a new concept to replace Upstream and Downstream
TerminalReceiver: a Receiver that outputs to a terminal
String: clarification
Buffer: fixed region()
TerminalReceiver: fixed compilation issue
JsonDb: added send() functions
JsonItem: fixed observer notifications
JsonObject: added name()
Merge branch 'master' into json