added SSL configurability

I needed to customize the SSL handling for the client and server (specifically to test out some TLS 1.2 functionality) but it could be used in general to control which SSL/TLS versions you want to use, which ciphers you want to use, client-side cert, etc.  Use like this:

	def server = vertx.createHttpServer( SSL: true, 
		keyStorePath: 'ecc.jks',
		keyStorePassword: 'test123' )

	server.sslConfigureInterceptor = { engine ->
			engine.enabledProtocols = ['TLSv1.2']//,'TLSv1.1','TLSv1']//,'SSLv3']
	/*		engine.enabledCipherSuites = [
				'TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256',
				'TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256',
				'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256',
				'TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256',
				'TLS_RSA_WITH_AES_128_CBC_SHA256',
	//			'TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA',
	//			'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA',
	//			'TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA',
	//			'TLS_ECDH_RSA_WITH_AES_128_CBC_SHA',
	//			'TLS_RSA_WITH_AES_128_CBC_SHA'
			]
	*/
			println "Enabled only:"
			println "  $engine.enabledProtocols"
			println "  $engine.enabledCipherSuites"
		} as SSLConfigureInterceptor