Toro et. al. 1997 GMPE as needed for the 2008 NSHMP-US model
changed class name from ToroEtAl1997NSHMP to ToroEtAl1997NSHMP2008
Merge pull request #169 from monellid/toro1997_nshmp

Toro et. al. 1997 GMPE as needed for the 2008 NSHMP-US model