only accept files of type image/* in ui multi-select;  change imgcoder default to use FileReader
image pastable into content-editable area?
integrated imgrecoder into topnav.
added imgrecoder to topnav; streamlined ui
add generic, default mimetype for FileReader readAsDataURL method.  this & protocol are  stripped when final results are returned.
first pass at detecting asset id by parsing input string as html.