Add flag style and colours to MusicXML export

[ccarlsen94]

I changed the style from "traditional" to "straight" and then changed the color of the flag.  When I exported the file to the uncompressed Music XML file there was not any coding for either the type of flag or the color of the flag (see below)

.  How do I add these elements into the xml file so it can be read correctly by MuseScore?

F 5 1 1 eighth up normal

[Jojo-Schmitz]

Straight flags don't seem to get exported to MusicXML
Neither do flag colors

[ccarlsen94]

I realize that so do I add the code for the straight flag and the color to the MusicXML code?

[Jojo-Schmitz]

See also w3c/musicxml#521, this (color of flags) issue seems to be down to a MusicXML restriction