Spec: clarify what an attempt by the realtime client to authenticate is

content/client-lib-development-guide/features.textile

@@ -147,7 +147,8 @@ h3(#rest-auth). Auth
 *** @(RSA4c1)@An @ErrorInfo@ with @code@ @80019@, @statusCode@ 401, and @cause@ set to the underlying cause should be emitted with the state change if there is one (per @RSA4c2/3@) and set as the connection @errorReason@
 *** @(RSA4c2)@If the connection is @CONNECTING@, then the connection attempt should be treated as unsuccessful, and as such the connection should transition to the @DISCONNECTED@ or @SUSPENDED@ state as defined in "RTN14":#RTN14 and "RTN15":#RTN15
 *** @(RSA4c3)@If the connection is @CONNECTED@, then the connection should remain @CONNECTED@
-** @(RSA4d)@ If a request by a realtime client to an @authUrl@ results in an HTTP 403 response, or any of an @authUrl@ request, an @authCallback@, or a request to Ably to exchange a @TokenRequest@ for a @TokenDetails@ result in an @ErrorInfo@ with @statusCode@ 403, then the client library should transition to the @FAILED@ state, with an @ErrorInfo@ (with @code@ @80019@, @statusCode@ 403, and @cause@ set to the underlying cause) emitted with the state change and set as the connection @errorReason@
+** @(RSA4d)@ If a request by a realtime client to an @authUrl@ results in an HTTP 403 response, or any of an @authUrl@ request, an @authCallback@, or a request to Ably to exchange a @TokenRequest@ for a @TokenDetails@ result in an @ErrorInfo@ with @statusCode@ 403, as part of an attempt by the realtime client to authenticate, then the client library should transition to the @FAILED@ state, with an @ErrorInfo@ (with @code@ @80019@, @statusCode@ 403, and @cause@ set to the underlying cause) emitted with the state change and set as the connection @errorReason@
+*** @(RSA4d1)@ An "attempt by the realtime client to authenticate" in @RSA4c@ and @RSA4d@ includes getting a token as part of the connect sequence, an @RTN22@ online reauth, and an explicit @authorize()@ call, but _not_ an explicit @requestToken@ call, which should have no effect on library state
 ** @(RSA4e)@ If in the course of a REST request (or explicit call to @requestToken@) an attempt to authenticate using @authUrl@ or @authCallback@ fails due to a timeout, network error, a token in an invalid format (per "RSA4f":#RSA4f), or some other auth error condition other than an explicit @ErrorInfo@ from Ably, the request should result in an error with @code@ 40170, @statusCode@ 401, and a suitable error message
 ** @(RSA4f)@ The following conditions imply that the token is in an invalid format: the @authUrl@ response content type is not one of @text/plain@, @application/json@ or @application/jwt@; the object passed by @authCallback@ is neither a @String@, @JsonObject@, @TokenRequest@ object, nor @TokenDetails@ object; the token string or the JSON stringified @JsonObject@, @TokenRequest@ or @TokenDetails@ is greater than 128KiB.
 ** @(RSA4g)@ If multiple @authOptions@ are used to initialize the library, the preference ordering among them is identical to @Auth#authorize@, defined in @RSA10e@