Minor cleanups.
Minor cleanups.

Specifically: Make the FiniteElement::clone() function public, as it is of
general use. Also: Move several member variables from private to protected
as these are generally variables that derived classes are supposed to
initialize; this allows to remove rather random friend declarations for
these derived classes.

EGP-CIG-REU/dealii,natashasharma/dealii,sairajat/dealii,nicolacavallini/dealii,shakirbsm/dealii,JaeryunYim/dealii,msteigemann/dealii,YongYang86/dealii,maieneuro/dealii,rrgrove6/dealii,shakirbsm/dealii,ibkim11/dealii,adamkosik/dealii,johntfoster/dealii,gpitton/dealii,shakirbsm/dealii,Arezou-gh/dealii,EGP-CIG-REU/dealii,kalj/dealii,angelrca/dealii,YongYang86/dealii,ibkim11/dealii,shakirbsm/dealii,natashasharma/dealii,rrgrove6/dealii,kalj/dealii,EGP-CIG-REU/dealii,natashasharma/dealii,nicolacavallini/dealii,jperryhouts/dealii,andreamola/dealii,Arezou-gh/dealii,pesser/dealii,johntfoster/dealii,mtezzele/dealii,rrgrove6/dealii,ibkim11/dealii,danshapero/dealii,adamkosik/dealii,JaeryunYim/dealii,sairajat/dealii,naliboff/dealii,adamkosik/dealii,mtezzele/dealii,kalj/dealii,sriharisundar/dealii,natashasharma/dealii,sriharisundar/dealii,naliboff/dealii,ibkim11/dealii,lue/dealii,jperryhouts/dealii,rrgrove6/dealii,angelrca/dealii,ibkim11/dealii,shakirbsm/dealii,maieneuro/dealii,Arezou-gh/dealii,ESeNonFossiIo/dealii,JaeryunYim/dealii,flow123d/dealii,spco/dealii,ESeNonFossiIo/dealii,kalj/dealii,angelrca/dealii,pesser/dealii,naliboff/dealii,ESeNonFossiIo/dealii,angelrca/dealii,Arezou-gh/dealii,naliboff/dealii,nicolacavallini/dealii,spco/dealii,gpitton/dealii,shakirbsm/dealii,johntfoster/dealii,msteigemann/dealii,YongYang86/dealii,danshapero/dealii,flow123d/dealii,lpolster/dealii,sriharisundar/dealii,YongYang86/dealii,natashasharma/dealii,JaeryunYim/dealii,ESeNonFossiIo/dealii,lpolster/dealii,gpitton/dealii,ibkim11/dealii,kalj/dealii,jperryhouts/dealii,flow123d/dealii,mtezzele/dealii,mtezzele/dealii,flow123d/dealii,adamkosik/dealii,mac-a/dealii,pesser/dealii,mac-a/dealii,danshapero/dealii,rrgrove6/dealii,msteigemann/dealii,ibkim11/dealii,danshapero/dealii,jperryhouts/dealii,sriharisundar/dealii,rrgrove6/dealii,flow123d/dealii,lpolster/dealii,mac-a/dealii,lue/dealii,pesser/dealii,lpolster/dealii,sairajat/dealii,Arezou-gh/dealii,EGP-CIG-REU/dealii,JaeryunYim/dealii,andreamola/dealii,shakirbsm/dealii,andreamola/dealii,sairajat/dealii,gpitton/dealii,YongYang86/dealii,mtezzele/dealii,spco/dealii,johntfoster/dealii,spco/dealii,maieneuro/dealii,danshapero/dealii,maieneuro/dealii,gpitton/dealii,lue/dealii,ESeNonFossiIo/dealii,andreamola/dealii,Arezou-gh/dealii,EGP-CIG-REU/dealii,msteigemann/dealii,adamkosik/dealii,msteigemann/dealii,maieneuro/dealii,lue/dealii,spco/dealii,naliboff/dealii,JaeryunYim/dealii,nicolacavallini/dealii,sairajat/dealii,natashasharma/dealii,YongYang86/dealii,nicolacavallini/dealii,andreamola/dealii,flow123d/dealii,pesser/dealii,johntfoster/dealii,ESeNonFossiIo/dealii,JaeryunYim/dealii,andreamola/dealii,sairajat/dealii,adamkosik/dealii,lue/dealii,mtezzele/dealii,sriharisundar/dealii,lpolster/dealii,ESeNonFossiIo/dealii,maieneuro/dealii,lue/dealii,flow123d/dealii,EGP-CIG-REU/dealii,lpolster/dealii,gpitton/dealii,pesser/dealii,danshapero/dealii,danshapero/dealii,YongYang86/dealii,andreamola/dealii,mac-a/dealii,Arezou-gh/dealii,jperryhouts/dealii,kalj/dealii,naliboff/dealii,mac-a/dealii,kalj/dealii,johntfoster/dealii,msteigemann/dealii,msteigemann/dealii,nicolacavallini/dealii,sriharisundar/dealii,sairajat/dealii,mac-a/dealii,lpolster/dealii,spco/dealii,adamkosik/dealii,rrgrove6/dealii,angelrca/dealii,gpitton/dealii,mtezzele/dealii,angelrca/dealii,angelrca/dealii,natashasharma/dealii,jperryhouts/dealii,johntfoster/dealii,pesser/dealii,EGP-CIG-REU/dealii,mac-a/dealii,nicolacavallini/dealii,sriharisundar/dealii,maieneuro/dealii,naliboff/dealii,jperryhouts/dealii,spco/dealii,lue/dealii