DataTable mixed Formatter and DateTimeFormatter

Hello,

I was looking over the documentation, discussion board and Github issues list for the following use case but could not find anything useful.

I have two use cases i tried to implement in the formatter options but could not find a way to implement them within bokeh library. My solution was simple enough to format the columndatasource as strings to get the behavior I needed.

1. I have a list of datetimes I wanted to display including some None values from a database. The formaters supported seemed to only provide Date or Time, not DateTime. The default value for None values results in a date at 1969 (bug?).

2. I then tried to provide a list of formatter objects to individually format the datatable rows individually. IE checkmarks and dates. This threw and error.