adding FSPS accepted revisions
add a hack to read the data in a .cmd file into a huge nunmpy array
add the tpagb_norm_type setup parameter, and remove older, now incompatible FSPS revs from the accepted list
fix the data type for the tpagb_norm setup check
add documentation for the tpagb_norm_type parameter
clean up the cmd method, make outfile a keyword, and remove unused code
add a call to _compute_csp() before writing out isochochrone, not sure why this is necessary
add r168 to rev list and change defualt tpagb_norm_type to be consistent with FSPS and older code versions
return isochrone data as structured ndarray following @jonathansick's suggestion
rename cmd() method to isochrones()
Merge pull request #23 from bd-j/master

StellarPopulation.isochrones() and tpagb_norm_type parameter