[BRLTTY] Speech enhancements

[Yannick PLASSIARD]

Hi all:
	It would be good to have a new setting "Echo by" in the configuration. Values could be :
* Character (as usual)
* Word 
* Character and word
	This could be better to have a good speech support , especially if we decide to make an "only-speech" based brltty (doing this with the PC keyboard enhancements which is in developpment).
 What do you think of this ? It seems not hard to do... Some volonteers ? :) If not but idea is agreed, I could do this.
Thanks :)