Jupyterthemes

- removed some excess fonts from sans-serif and serif collections
- added option for setting pandas dataframe font-size (-dfs , --dffontsize)
- added option for output area font-size (-ofs , --outfontsize)
- minor cosmetic improvements

- all fonts now default to whatever browser defaults are (users can still specify custom code-cell (-f), text-cell (-tcf), and notebook (-nbf) fonts as before).
- improved prompt style for text cells
- re-compiled css for binder
- minor cosmetic improvements

- improved kernel and notification widget alignment
- added helvetica, helveticaneue fonts
- fixed bug that prevented install if fontname not recognized
- added compatibility for hide_header nbext
- minor cosmetic improvements

- made changes to solarizedd style

- added solarized-dark theme "jt -t solarizedd" ([PR 103](https://github.com/dunovank/jupyter-themes/pull/103) submitted by [raybuhr](https://github.com/raybuhr))
- fixed jupyter-soft-selected style (multiple cell selected)
- modified table style
- deprecated -alt/--altlayout (use -altp/--altprompt for smaller prompts, no number)

- fixed bug that prevented fonts from being imported correctly