fun issues...

fun issues...
(1) need to compute promises for rmw nodes...they could satisfy them
(2) don't call rmwedge if you don't know where you are reading from yet
(3) miscopied commit from big merge (already_added -> !already_added)
(4) avoid adding rmw edges back to itself
(5) probably worth adding a check that the execution isfeasible before sending future values
(6) resolve promises should add rmwedges when appropriate
(7) fix seq_cst to mask earlier writes..