Comment formatting for general notes/deductions

[hmontero1205]

When deducting a comment, also annotate the numeric point deduction so that students don't have to cross-reference rubric just to double-check arithmetic.

e.g. instead of just (C3) <comment>

have it dump (C3: -4) <comment>

and then have a different syntax for no point deduction, e.g.:

[A3: 0] <comment without point deduction>