added IDs for groups and people as well as the ability to check if a student is in a given group, or if a group contains a given student
Merge branch 'master' of https://github.com/mbrown7/IndependentStudy

Conflicts:
	src/edu/umw/cpsc/collegesim/Person.java
Merge branch 'master' of https://github.com/mbrown7/IndependentStudy

Conflicts:
	src/edu/umw/cpsc/collegesim/Group.java
	src/edu/umw/cpsc/collegesim/Person.java