Add a polymorphism exercise to inheritance lab.
Add full reading on loop invariants.
Add lab on quadratic sorts.
Add lab on merge sort.
Add reading on lists.
Minor update to git reading.
Minor cleanup to reading on stacks.
Add reading on generics.
Add reading on mergesort.  (Written a month ago.  Whoops.)
Add reading on sorting (written a month ago, whoops).
Clean up code in reading on anonymous inner classes.
Minor updates to code in reading on lists.
Clean up code in reading on searching.
Minor code cleanup in reading on polymorphism.
Added note to self in reading on loop invariants.
Add lab on generics (written a month ago; whoops).
Add lab on array based lists (written a few weeks ago).
Add lab on linked lists (written a few weeks ago).
Minor updates to lab on Quicksort, including a question on what pivot to use.
Clean up code in binary search lab.