Partnered with Nick Cornhill 

Got the 5 problems from 11.2.2 implemented with testing!
Added the random methods for Ian & Phou
added superclass for vector problems.
finished all edits suggested (except using closeTo in the tests for
Schwefel and Griewank)
Removed private from bound() method and added a def that was needed.
Should probably be private, but we don't know how to do that. Without
this change, nothing works.
Merge remote-tracking branch 'RenjiClark/Nick&AlexBranch!' into
chap-11-problems

Conflicts:
	EssentialsOfMetaheuristics/src/problems/BitStringProblem.groovy
	EssentialsOfMetaheuristics/src/problems/Rastrigin.groovy
	EssentialsOfMetaheuristics/src/problems/Sum.groovy

Resolving these conflicts was a bit of a pain because two different
threads of development had gone different directions, but I think we're
good now.
Added a test for Sum, and in the process identified a bug and fixed it,
along with replacing a bogus comment. We were returning the positive sum
when we were supposed to negate the sum.
Added a test for Rastrigin.