Made OptsCompleter more robust to OptionsTree KeyErrors
Made OptsCompleter more robust to OptionsTree KeyErrors

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