Improved validation of fontsize keys
Improved validation of fontsize keys

vascotenner/holoviews,vascotenner/holoviews,ioam/holoviews,ioam/holoviews,ioam/holoviews,basnijholt/holoviews,vascotenner/holoviews,basnijholt/holoviews,basnijholt/holoviews