disable clang warnings
disable clang warnings

compiling the bundled boost with clang without cxx11 causes hundreds of
warnings.

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