Chrisbase

- Update get_current_path(): work robustly!
- Add is_notebook()
[https://stackoverflow.com/questions/15411967/how-can-i-check-if-code-is-executed-in-the-ipython-notebook]

- Update remove_dir_check(): verbose, real option

- Fix import error
- Add remove_dir_check()
- Add OK(), OX(), ox()

- Relative import
- Update display_histogram()

- Add trim_output(), after(), before()
- Update to_dataframe()

- MyTimer print into one file!