Add noise test source to simpletest. Add xtract_flux() example to simpletest
Add noise test source to simpletest. Add xtract_flux() example to simpletest

eriser/LibXtract,kecsap/LibXtract,jamiebullock/LibXtract,caseybasichis/LibXtract,jamiebullock/LibXtract,caseybasichis/LibXtract,caseybasichis/LibXtract,kecsap/LibXtract,kecsap/LibXtract,eriser/LibXtract,eriser/LibXtract,jamiebullock/LibXtract