combining several exps

[ransona]

1. use config_example_run_step1_combined.py to combine exps that you want to register together in step 1 of pipeline
2. curate rois in suite2p (of combined suite2p output)
3. split using split_combined_s2p.py
4. run step 2 of pipeline

[ransona]

still to be added is dealing with 2 chs when splitting