Fix unhandled error during client connection
Fix unhandled error during client connection

Client actions utilizing an EventEmitter may generate unhandled errors,
especially during initial connection.  Tracking whether the emitter has
been sent via callback is critical for proper routing of such errors.

Fix mcavage/node-ldapjs#144

appcelerator/node-ldapjs,brion25/node-ldapjs,tempbottle/node-ldapjs,simonbooth/node-ldapjs,917228145/node-ldapjs,cloudron-io/node-ldapjs,DrHofman/node-ldapjs,mcavage/node-ldapjs,pfmooney/node-ldapjs,hoalex/node-ldapjs,narcisoguillen/node-ldapjs,msimerson/node-ldapjs