generators lab

Commit file needed for generator branch.
Merge branch 'master' into gens

Conflicts:
	include.tex
introduce itertools

Introduce the itertools library from the Python Standard Library.  We
should probably add a problem or two that use the iterators from
itertools.
update explanation of generators

Describe generators a little more in detail.  Removed a less than useful
problem.
added another generator problem

Implemented a problem idea suggested by Jason Grout.  Made a gray code
generator that is much faster and more general.
huge speedup by using Python 2.7 feature

Used a feature of Python 2.7 to find the highest bit set of an integer.
remove unused import

math.log is not used anywhere.

Also added some whitespace by suggestion of pep8
found another way to cite Brualdi's book

Need a way to cite books that are referenced in the lab.  Right now, we
are going to do footnote citations, but it would be nice to have a
References section at the end of each lab.
improve clarity of a problem in generator lab

Reworded a problem to make it clearer to a reader.
Merge branch 'gens' of git://github.com/ayr0/numerical_computing into generators
Edits to the generators lab
Merge pull request #2 from insertinterestingnamehere/generators

Genorators lab edits
updates to generators lab

Some further improvements to the generators labs.  Fixed various errors
and some other typos.
Merge pull request #81 from ayr0/gens

Update for generator lab
Merge branch 'master' into statslabs