removes unnecessary __init__s from searchers
inits PSO
searhcer shortnames in __init__ were a bad idea
makes IV's lo and hi 'read-only'
changes IV's 'type' attribute to '_type'
docstrings for IV's lo and hi
removes unnecessary default values from IV
adds docstring with doctest to IV
more specific exceptions for out-of-range model io
adds error checking for random_model_io
docstrings for model methods
init Particle class for PSO
calculates shortnames at search time
adds new options to config for PSO
adds iterator for Log
adds random_replace to Model
implements PSO
fixes era logging bug in SA
moves tests for models to their own files
adds tests for random_replace