Newly created notebooks no longer error on saving - bug in how
kernelspec metadata was being filled in.
Also a number of miscellaneous fixes to indentation that have
inexplicably appeared in the code.
Some small fixes for typos and catching up on version info.
NBformat 4 has a tag key in the cell metadata. We use it to tag a cell
depending on which worksheet it is in. For now the code does nothing
else with this tag, but the goal is to reimplement multiple worksheets
in ein.
