Add Fraction test: negative
Add Fraction tests: multiply(...)
Fix error in FractionTest.testToDouble by adding ".0"

I was using integer divisions in the "known-good" states of the test
cases, so I was comparing doubles from toDouble against ints.

That never ends well.

Fixed.
Minor change to behavior of Fraction.toDouble

The original method added the unit to the quotient of the numerator and
denominator. I realized that this resulted in round-off error, as my
unit tests indicated (1.666...6665 [1 + 2.0/3] != 1.666...6667 [5.0/3]),
and chose to change this to evaluate the entire expression as an
improper division.
Add Fraction tests: divide(...)
Fraction.divide(Fraction) should throw ArithExc, not IllArgExc
Add ArrayUtils.lengthArray

This will come in handy for Sweepstakes, which takes a *condensed*
length array (coming up next).
Add ArrayUtils.condensedLengthArray (undocumented as of now)
Make checkTies() accept Object[][], not String[][]

[begin self-deprecating rant]

Seriously, MathSquared? What were you thinking?

There is LITERALLY NO REASON why checkTies has to take only String[][].

Sure, I was intending to use this to, you know, check for correctly
formatted ties in results...

...but WHY can't it accept any other objects too?

Strings are Objects, bro.

[end self-deprecating rant]
Add a tie check to ArrayUtils.condensedLengthArray(Object[][])

This was intended from early on, until I saw that stupid me made
checkTies() take String[][] and had to fix that in the preceding commit.
Document condensedLengthArray(...)