Major update to main extraction script.

Updated a lot of user-facing text, and removed obsolete information.
Rearranged presentation of script options.
Now uses makeplot for plotting.
Now prints model uncertainties after extraction.
Now terminates if user-specifed baseline, peak function, or model evaluator cannot be imported.
Moved around some imports, including one that caused a bug with liveplots.

Author: Ainamacar