+++++++++++++++++++
**Improvements**
- Jupyter magic commands escaped when exported (29)
- 'endofcell' option for explicit (optional) end-of-cell marker (31)
- 'active' cell option now supported for .py and .R export (30)
- Raw cells now preserved when exported to .py or .R (32)
- Extensions can be prefixed, like `.nb.py`, (mwouts/nbsrc5)
- When a file with an extension not associated to 'ipynb' is opened and saved,
no 'ipynb' file is created (mwouts/nbsrc5)
- Extensions can now be a sequence of groups. For instance,
`nbrmd_formats="ipynb,nb.py;script.ipynb,py"` will create an `ipynb` file
when a `nb.py` is opened (and conversely), and a `script.ipynb` file when a
`py` file is opened (mwouts/nbsrc5)
- `nbsrc` script was moved to the `nbrmd` package. The `nbsrc` package now only
contains the documentation (mwouts/nbsrc3)