[Rich Content Editor] Restore Math Editor Functionality

[ssnyder2]

The new Equation Editor is nice, but we've lost a couple of features that are quite useful if you enter a lot of equations into your courses.

1.) In the previous version, once you selected "Advanced" to enter equations using LaTex, it remained in the Advanced state for future equations on the same quiz, discussion, etc.  Now, I have to click on "Directly Edit LaTex" every time, which is a pain to remember if you're typing quickly.

2.)  Quite often, I need to type several lines of equations when demonstrating how to simplify an expression or solve an equation.  So, I need to be able to see the previous line(s) while typing a new equation.  The previous version allowed me to move the Equation Editor window around my screen.  The new version won't let me, so I have to keep writing the math out on paper and typing it into the editor.  The extra time adds up....