initialize isoch-fitting func
rm not needed code: data stored in files
rm 1% variation calculation to be replaced by bootstrap
rm data read from files
rm deprecated else statement
move isoch reading to new function
move ranges and paths reading to new func
move move_track to new func
del intrinsic_values func, not needed anymore
call get_ranges_paths from within read_isochrones
functions position rearrange
functions position rearrange 2
move data read into new func
move brute force algor to new func
define brute_force and isoch_likelihood functions
outline of necessary functions
minor fixes to isoch fitting func
write down likelihood equations
minor corrections to likelihood func
def Kroupa et al 1993 IMF