Added non connection derived OTR key support. Following options added
* this.session_pass_as_otr_pass = true;
* this.otr_pass_storage_name = undefined; // set this to customize OTR passphrase location (good for integration with other platforms)
* this.otr_pass_max_tries = 3;

The code on getSession was altered to support custom OTR phrases. see commit diff