gs issues

[ClimbsRocks]

parallelism doesn't work. probably need to bring back copy_reg stuff. we didn't catch this because our test suite runs single-threaded, because nested parallelism fails.

the user has to pass in model__ for each param name for gs_params. make this easier by checking for model__ and, updating the param name accordingly.

[xialeizhou]

opps ~~~ this project has so many bugs~