[smartdown] also process ID/Class on math elements
[smartdown] also process ID/Class on math elements

alexjobs/deck.js-1,twitwi/deck.js,ProgRT/deck.js,twitwi/deck.js,ProgRT/deck.js,twitwi/deck.js,ProgRT/deck.js,alexjobs/deck.js-1,alexjobs/deck.js-1