created testing branch
created Notebook class
added text_utils.py
added text_utils.py
separated command handling into classes
code clean-up
added bibtex-to-bibnote converter
fixed multiple errors with bibliography
lots of small fixes and improvements in bibliography
added tag/keyword list in bibliography
bibliography can be saved in html
simplified error handling from write_notebook
implemented save_bibtex function
simplified notebook saving function
implemented delete function in bibliography
bibliography can be saved as stand-alone html
added json_to_bibtex function
added bibtex parser to Bibtex tab
fixed bibtex parser in Bibtex tab
tags work now, though a bit slowly...