mobizt/Firebase-ESP8266: v3.4.0

v3.4.0 major update, stable release

• Code optimization and refactoring.
• Bugs fixed e.g. prevent zero length data sent in TCP client.
• Major updates with features added and improvement in FirebaseJson, RTDB and Session classes.
• Reduce memory usage.
• Features added e.g. FirebaseData object's setCert() for locally Root CA verification, to<type>() for any value casting.
• RTDB Data type checking is now optional.
• Fixed queue management code and file structure.
• Rewrite and update examples.
• MultipathStream begin and callback functions updated.
• FireSense class and example updates. The loadConfig function with default config callback function as argument is set to deprecate.
• Searchable Json object and array supported.
• FirebaseJsonData casting to any value type is now supported.
• FirebaseJson object and array serialize to writable object and deserialize from readable stream and client are supported.