[ossia-max] add @echo attribute to remote

[avilleret]

as discussed in #784 we need an @echo attribute to ø.remote to avoid value output when it is changed by sending a value. This is a request from @matcham to fix stopping automation in Live.

This attribute should be 1 in Max and 0 in Live by default.

[matcham]

thanks for considering my FR :-)

I don't think that the default value of this attribute should change depending if the patch is in Max or in Live.
It would make things very difficult to debug (what would happen when u edit / open a live device in Max ? is it Max or Live ?).
Echo is an issue only when connecting live.ui objects to a remote (and using automation) ; @echo 0 should be used only in this case.