Properly clear old constraints when recalculating
Properly clear old constraints when recalculating

This fixes two bugs:

A bug in master, where we fail to clear constraint coefficients
properly when the last constraints are removed from a 1D problem
(basically impossible to trigger)

A bug in adjoint_dirichlet, where we fail to clear heterogenous
constraint rhsvalues properly, ever (destroying solutions)

cahaynes/libmesh,friedmud/libmesh,salazardetroya/libmesh,capitalaslash/libmesh,cahaynes/libmesh,vikramvgarg/libmesh,capitalaslash/libmesh,dschwen/libmesh,jiangwen84/libmesh,Mbewu/libmesh,pbauman/libmesh,dmcdougall/libmesh,svallaghe/libmesh,salazardetroya/libmesh,hrittich/libmesh,coreymbryant/libmesh,salazardetroya/libmesh,libMesh/libmesh,dschwen/libmesh,coreymbryant/libmesh,dmcdougall/libmesh,friedmud/libmesh,permcody/libmesh,Mbewu/libmesh,BalticPinguin/libmesh,jiangwen84/libmesh,giorgiobornia/libmesh,cahaynes/libmesh,coreymbryant/libmesh,svallaghe/libmesh,dknez/libmesh,roystgnr/libmesh,pbauman/libmesh,permcody/libmesh,dmcdougall/libmesh,balborian/libmesh,aeslaughter/libmesh,90jrong/libmesh,pbauman/libmesh,balborian/libmesh,salazardetroya/libmesh,giorgiobornia/libmesh,karpeev/libmesh,vikramvgarg/libmesh,vikramvgarg/libmesh,dmcdougall/libmesh,90jrong/libmesh,jwpeterson/libmesh,permcody/libmesh,roystgnr/libmesh,aeslaughter/libmesh,capitalaslash/libmesh,Mbewu/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,capitalaslash/libmesh,capitalaslash/libmesh,karpeev/libmesh,libMesh/libmesh,friedmud/libmesh,coreymbryant/libmesh,cahaynes/libmesh,Mbewu/libmesh,benkirk/libmesh,roystgnr/libmesh,hrittich/libmesh,hrittich/libmesh,90jrong/libmesh,giorgiobornia/libmesh,permcody/libmesh,benkirk/libmesh,benkirk/libmesh,aeslaughter/libmesh,aeslaughter/libmesh,friedmud/libmesh,giorgiobornia/libmesh,permcody/libmesh,roystgnr/libmesh,karpeev/libmesh,pbauman/libmesh,dknez/libmesh,dknez/libmesh,jwpeterson/libmesh,balborian/libmesh,roystgnr/libmesh,coreymbryant/libmesh,friedmud/libmesh,pbauman/libmesh,cahaynes/libmesh,permcody/libmesh,roystgnr/libmesh,salazardetroya/libmesh,dknez/libmesh,Mbewu/libmesh,salazardetroya/libmesh,aeslaughter/libmesh,jiangwen84/libmesh,dmcdougall/libmesh,libMesh/libmesh,vikramvgarg/libmesh,benkirk/libmesh,coreymbryant/libmesh,BalticPinguin/libmesh,svallaghe/libmesh,giorgiobornia/libmesh,coreymbryant/libmesh,svallaghe/libmesh,svallaghe/libmesh,balborian/libmesh,Mbewu/libmesh,libMesh/libmesh,Mbewu/libmesh,vikramvgarg/libmesh,vikramvgarg/libmesh,giorgiobornia/libmesh,salazardetroya/libmesh,giorgiobornia/libmesh,hrittich/libmesh,friedmud/libmesh,BalticPinguin/libmesh,permcody/libmesh,libMesh/libmesh,giorgiobornia/libmesh,dschwen/libmesh,dmcdougall/libmesh,dknez/libmesh,karpeev/libmesh,svallaghe/libmesh,vikramvgarg/libmesh,coreymbryant/libmesh,balborian/libmesh,hrittich/libmesh,BalticPinguin/libmesh,benkirk/libmesh,dschwen/libmesh,friedmud/libmesh,svallaghe/libmesh,svallaghe/libmesh,dschwen/libmesh,dschwen/libmesh,90jrong/libmesh,capitalaslash/libmesh,cahaynes/libmesh,benkirk/libmesh,libMesh/libmesh,90jrong/libmesh,cahaynes/libmesh,BalticPinguin/libmesh,balborian/libmesh,jwpeterson/libmesh,karpeev/libmesh,pbauman/libmesh,hrittich/libmesh,dmcdougall/libmesh,90jrong/libmesh,balborian/libmesh,libMesh/libmesh,friedmud/libmesh,jwpeterson/libmesh,karpeev/libmesh,jiangwen84/libmesh,pbauman/libmesh,salazardetroya/libmesh,jiangwen84/libmesh,dschwen/libmesh,balborian/libmesh,dknez/libmesh,dmcdougall/libmesh,aeslaughter/libmesh,benkirk/libmesh,dschwen/libmesh,hrittich/libmesh,capitalaslash/libmesh,karpeev/libmesh,giorgiobornia/libmesh,vikramvgarg/libmesh,balborian/libmesh,roystgnr/libmesh,90jrong/libmesh,vikramvgarg/libmesh,Mbewu/libmesh,aeslaughter/libmesh,Mbewu/libmesh,BalticPinguin/libmesh,hrittich/libmesh,friedmud/libmesh,aeslaughter/libmesh,jiangwen84/libmesh,jiangwen84/libmesh,dknez/libmesh,permcody/libmesh,benkirk/libmesh,pbauman/libmesh,90jrong/libmesh,karpeev/libmesh,pbauman/libmesh,dknez/libmesh,libMesh/libmesh,capitalaslash/libmesh,roystgnr/libmesh,aeslaughter/libmesh,cahaynes/libmesh,svallaghe/libmesh,BalticPinguin/libmesh,jiangwen84/libmesh,benkirk/libmesh,hrittich/libmesh,90jrong/libmesh,balborian/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,jwpeterson/libmesh