Amplpy

- Update internal library.
- Add AMPL.exportModel.
- AMPL.exportData now supports indexed sets.

- Improve AMPL.exportGurobiModel and AMPL.importGurobiSolution.
- Add verbose option to AMPL.exportGurobiModel.
- Add register_magics to register `%%ampl` and `%%ampl_eval`.

- Fix dll loading issue with python versions that come with conda.

- Fix issue with indexed sets (by updating the internal library).

- Add support for Pandas Series.
- Add optional gurobiDriver parameter to AMPL.exportGurobiModel.

- Improve robustness of AMPL.exportGurobiModel.
- Improve error message when AMPL is not in the search path.