Support out of source builds
Created by: Munken
Trying to do a out of source build fails with this message:
make
[ 1%] Generating NPVDetectorDict.cxx
/bin/sh: 1: ../scripts/build_dict.sh: not found
make[2]: *** [Core/NPVDetectorDict.cxx] Error 127
make[1]: *** [Core/CMakeFiles/NPCore.dir/all] Error 2
make: *** [all] Error 2
Guess the cmake script for making dicts should be modified to use CMAKE_SOURCE_DIR