Make build_extrusion work for 1D->2D extrusion.
Make build_extrusion work for 1D->2D extrusion.

Refs #259.

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