compile with c++11 as the standard
Fixed some implicit casts in CeperleyMatrix.hpp that no longer seem to work with C++11

See Eigen thread "Convert 1x1 matrix to internal type?"
migrated to std::unique_ptr, since std::auto_ptr is deprecated in C++11
further c++11 changes in CeperleyMatrix.hpp
use "override" and "final" on virtual functions as appropriate (new in c++11)
Merge branch 'master' into c++11
Merge branch 'master' into c++11
Merge branch 'master' into c++11