LiveQuery: "already connecting"

[fischerscode]

Currently "_connecting" (parse_live_query.dart) is not properly handled properly.
This results in a state where the client can't establish a new connection to the server.

How to reproduce:

1. connect to the livequery-server
2. disconnect the client from the internet
3. reconnect the client to the internet
4. you won't be able to reconnect to to the livequery-server
   (Tested on an android emulator)

The Problem:

• the IOWebSocketChannel crashes and calls onDone
• _userDisconnected is false => reconnect is called
• _connecting is set to true
• WebSocket.connect fails => catch called

reactivate wifi => onConnectivityChanged fires event

• reconnect is called
• BUT _connecting is still true => _connect is canceled

Similar problems occur when the server crashes.
(and at some other times? (not sure))

How to fix it:
My suggestion is:

• set _connecting to false in the catch block
• adding a timeout to WebSocket.connect (in case the server is down)
• set _connecting to false after WebSocket.connect is done
• remove "_connecting = false;" inside _handleMessage
• adding some kind of delayed reconnect inside the catch block (in _connect)

Any other ideas?

[fischerscode]

#316 is merged