Merge pull request #198 from ably/clarify-echo

Clarify how `echoMessages` should be implemented

textile/features.textile

@@ -402,7 +402,7 @@ h3(#realtimeclient). RealtimeClient
 
 * @(RTC12)@ Has the same constructors as @RestClient@, as defined in "RSC1":#RSC1
 * @(RTC1)@ Supports all the same @ClientOptions@ as the @RestClient@ in addition to:
-** @(RTC1a)@ @echoMessages@ boolean is true by default. If false, it prevents messages originating from this connection being echoed back on the same connection
+** @(RTC1a)@ @echoMessages@ boolean is true by default. If false, it prevents messages originating from this connection being echoed back on the same connection; see "RTN2b":#RTN2b.
 ** @(RTC1b)@ @autoConnect@ boolean is true by default. If true, as soon as the client library is instantiated, it will connect to Ably. If false, the client library will wait for an explicit @Connection#connect@ to be called before connecting
 ** @(RTC1c)@ @recover@ string, when set, will attempt to recover the connection state of a previous connection
 ** @(RTC1d)@ @realtimeHost@ string, when set, will modify the realtime endpoint host used by this client library
@@ -444,7 +444,7 @@ h3(#realtime-connection). Connection
 * @(RTN1)@ @Connection@ connects to the Ably service using a "websocket":https://ably.com/topic/websockets connection. The "ably-js library":https://github.com/ably/ably-js supports additional transports such as Comet and XHR streaming; however non-browser client libraries typically use only a websocket transport
 * @(RTN2)@ The default host used for realtime "websocket":https://ably.com/topic/websockets connections is @realtime.ably.io@, and the following query string params should be used when opening a new connection:
 ** @(RTN2a)@ @format@ should be @msgpack@ (default) or @json@
-** @(RTN2b)@ @echo@ should be @true@ by default; @false@ will prevent messages published by the client being echoed back
+** @(RTN2b)@ @echo@ should be @true@ if the @echoMessages@ client option is true; else it should be @false@, which will prevent messages published by the client being echoed back
 ** @(RTN2d)@ @clientId@ contains the provided @clientId@ option of @ClientOptions@, unless @clientId@ is @null@
 ** @(RTN2e)@ Depending on the authentication scheme, either @accessToken@ contains the token string, or @key@ contains the API key
 ** @(RTN2f)@ The API version param @v@ must be included in all connections to Ably endpoints. The value to be sent is defined by "@CSV2@":#CSV2.