Remove PetscMatrix::update_preallocation_and_zero().
Remove PetscMatrix::update_preallocation_and_zero().

This feature was either never merged into PETSc upstream or completely
re-imagined, see the discussion on #605.  Instead of removing the API
entirely, we replace it with libmesh_not_implemented().  No
applications should have been relying on this feature, since it never
actually worked...

Brief history of this function:
3fa33444 - Originally added by @dknez
b3112f21 - Hacks to force matrix to reset by @karpeev

vikramvgarg/libmesh,pbauman/libmesh,dschwen/libmesh,balborian/libmesh,90jrong/libmesh,BalticPinguin/libmesh,vikramvgarg/libmesh,roystgnr/libmesh,giorgiobornia/libmesh,capitalaslash/libmesh,BalticPinguin/libmesh,svallaghe/libmesh,libMesh/libmesh,capitalaslash/libmesh,benkirk/libmesh,capitalaslash/libmesh,giorgiobornia/libmesh,roystgnr/libmesh,roystgnr/libmesh,90jrong/libmesh,giorgiobornia/libmesh,benkirk/libmesh,dschwen/libmesh,giorgiobornia/libmesh,dschwen/libmesh,vikramvgarg/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,libMesh/libmesh,benkirk/libmesh,BalticPinguin/libmesh,libMesh/libmesh,jwpeterson/libmesh,pbauman/libmesh,90jrong/libmesh,pbauman/libmesh,capitalaslash/libmesh,roystgnr/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,benkirk/libmesh,BalticPinguin/libmesh,balborian/libmesh,pbauman/libmesh,vikramvgarg/libmesh,hrittich/libmesh,benkirk/libmesh,capitalaslash/libmesh,dschwen/libmesh,90jrong/libmesh,benkirk/libmesh,balborian/libmesh,balborian/libmesh,benkirk/libmesh,svallaghe/libmesh,libMesh/libmesh,balborian/libmesh,svallaghe/libmesh,pbauman/libmesh,benkirk/libmesh,svallaghe/libmesh,benkirk/libmesh,dschwen/libmesh,libMesh/libmesh,balborian/libmesh,90jrong/libmesh,capitalaslash/libmesh,pbauman/libmesh,vikramvgarg/libmesh,giorgiobornia/libmesh,dschwen/libmesh,svallaghe/libmesh,svallaghe/libmesh,90jrong/libmesh,libMesh/libmesh,vikramvgarg/libmesh,90jrong/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,libMesh/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,vikramvgarg/libmesh,balborian/libmesh,giorgiobornia/libmesh,jwpeterson/libmesh,dschwen/libmesh,hrittich/libmesh,dschwen/libmesh,hrittich/libmesh,capitalaslash/libmesh,capitalaslash/libmesh,balborian/libmesh,hrittich/libmesh,90jrong/libmesh,svallaghe/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,svallaghe/libmesh,90jrong/libmesh,libMesh/libmesh,balborian/libmesh,pbauman/libmesh,hrittich/libmesh,pbauman/libmesh,BalticPinguin/libmesh,vikramvgarg/libmesh,vikramvgarg/libmesh,pbauman/libmesh,hrittich/libmesh,roystgnr/libmesh,balborian/libmesh,giorgiobornia/libmesh,hrittich/libmesh,hrittich/libmesh,svallaghe/libmesh,hrittich/libmesh,giorgiobornia/libmesh,giorgiobornia/libmesh,roystgnr/libmesh,roystgnr/libmesh