Merge pull request #37 from Dick-Lane/master

Add "simplified" to task sentence.
Mode is now unique.
All problems in Chap7Sec4 were categorized as Trigonometric Substitution,
but it's obvious that they are all partial fractions problems.
Fix miscategorization of problem Michigan/Chap7Sec8/Q29.pg
Merge pull request #38 from paulvojta/master

Fix DBsection tagging of some Michigan problems
Solutions added/modified.
Fix bug 2810, incorrect answer
New function composition problem.
New function equation problems.
Fix keywords.
Identify annual factor and distinguish it from effective rate per year.