Allow non binary tiddlers to be sent with their content type
Allow non binary tiddlers to be sent with their content type

This follows the same rules as the binary tiddler handling support added
in 221f38b, but if the tiddler is text based, uses send_data instead of
send_file.

This also adds another rule such that if the tiddler is markdown, it
always defaults to html rendering.

bengillies/federacy,bengillies/federacy