More parallel_sync in scatter_constraints
More parallel_sync in scatter_constraints

This replaces the last round-robin code in libMesh.

On the fifteenth day of Refactormas, my coder gave to me
Fifteen miscounted verses
Fourteen dead horses beaten,
Thirteen jokes run into the ground,
Twelve servers humming,
Eleven types duck-typing,
Ten threads unsleeping,
Non-blocking enhancing,
Eight commits made filking,
Syncin' once and winning,
Sexy accelerating,
Fie on all them pings!
Step (4) calling pull()s,
Three-D key syncing,
Two id types loved,
And a better way to set DoF ID.

giorgiobornia/libmesh,hrittich/libmesh,hrittich/libmesh,90jrong/libmesh,BalticPinguin/libmesh,giorgiobornia/libmesh,giorgiobornia/libmesh,roystgnr/libmesh,BalticPinguin/libmesh,dschwen/libmesh,jwpeterson/libmesh,libMesh/libmesh,capitalaslash/libmesh,pbauman/libmesh,roystgnr/libmesh,dschwen/libmesh,90jrong/libmesh,90jrong/libmesh,jwpeterson/libmesh,hrittich/libmesh,libMesh/libmesh,capitalaslash/libmesh,libMesh/libmesh,dschwen/libmesh,BalticPinguin/libmesh,hrittich/libmesh,libMesh/libmesh,pbauman/libmesh,giorgiobornia/libmesh,pbauman/libmesh,dschwen/libmesh,pbauman/libmesh,BalticPinguin/libmesh,90jrong/libmesh,capitalaslash/libmesh,hrittich/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,pbauman/libmesh,90jrong/libmesh,90jrong/libmesh,pbauman/libmesh,roystgnr/libmesh,jwpeterson/libmesh,giorgiobornia/libmesh,capitalaslash/libmesh,capitalaslash/libmesh,90jrong/libmesh,giorgiobornia/libmesh,roystgnr/libmesh,hrittich/libmesh,giorgiobornia/libmesh,giorgiobornia/libmesh,jwpeterson/libmesh,giorgiobornia/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,capitalaslash/libmesh,BalticPinguin/libmesh,hrittich/libmesh,90jrong/libmesh,capitalaslash/libmesh,jwpeterson/libmesh,roystgnr/libmesh,hrittich/libmesh,libMesh/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,capitalaslash/libmesh,dschwen/libmesh,dschwen/libmesh,90jrong/libmesh,hrittich/libmesh,jwpeterson/libmesh,pbauman/libmesh,libMesh/libmesh,pbauman/libmesh,libMesh/libmesh,libMesh/libmesh,jwpeterson/libmesh,pbauman/libmesh,dschwen/libmesh,roystgnr/libmesh,dschwen/libmesh