Generate FractionTest

This will be a fun test suite to implement...
Regenerate FractionTest with Javadoc templates
Add Fraction tests: constructors, toDouble, equals
Add Fraction tests: pow, reciprocal
Add more to FractionTest.testEqualsObject
Add double-negative test to FractionTest.testFractionIntInt
Check unit in all constructor tests in FractionTest
Add Fraction tests: extractUnit & co, getImproperNumerator