Added new lab called FourierExtensions.
This time I actually added the new files...
add more whitespace between paragraphs

Also pad the problem boxes so they look less crowded.

We add extra space between paragraphs to give a less dense feel of the
text material.  The space is minimal so it doesn't inflate the total
page count by too much.  It helps the labs read easier.
Added images to the lab, including the plotFigs file.
Merge pull request #383 from ayr0/para_spacing

add more whitespace between paragraphs
Made some various minor changes to the Lab text. Created a new image and
included in the lab.
Merge pull request #382 from abefrandsen/cepstrum

Added FourierExtensions lab.
Could use another look-over. The Cepstrum section can be improved, and the 2D FFT can be expanded.
Fixed a couple of errors in the solutions file to Fourier Extensions.
Merge pull request #384 from abefrandsen/cepstrum

Fixed a couple of errors in the solutions file to Fourier Extensions.
update makelab script

Recent changes in the tex packages included for the labs broke
makelab.py.  This commit fixes those issues.
Merge pull request #385 from ayr0/makelab

update makelab script