Compile issues with Clang

Fix compile issues found when compiling with clang -std=c++11

This commit fixes errors, several warnings still exist.

Details: Clang v 3.5
         openmpi-1.8.1
         Trilinos option:     -D Trilinos_ENABLE_CXX11:BOOL=ON

[gahanse@cee-compute011 ~]$ module list
Currently Loaded Modulefiles:
  1) sierra-compiler/clang/3.5    3) viz
  5) sierra-valgrind/3.9.0
  2) sierra-mkl/15.0-2015.0.090   4) sierra-git/2.0.0