Reconnecting features

Expose an endpoint to allow reseting the reconnect timer and reconnecting immediately.
Emit events when connecting and reconnecting with a timeout.
Build and bump minor version for new features.

Part of https://github.com/stellar/stellar-client/issues/918.
Consider emitting a more concise event name than "reconnecting". This even occurs after a connection attempt fails and an attempt retry connecting has been scheduled. For context the existing event names are "connected", "connecting, and "disconnected".
 - "connecting-failed"?
 - "connection-retry"?
 - "reconnection-scheduled"?