Add format toolbar buttons as in MS Word (e.g., Bold, Italics) for 'highlight'
and 'bold highlight' so that a phrase can be selected, and then a toolbar
button can be clicked to highlight it.
Have toggle mode between showing % and $ and displaying in RTF style.
Add another character such as '@' to preserve case.
On import sequences, if from SD or text file, prompt for difficulty level - don't always assume Medium.
