Spacing, line-break, and labeling style fixes in the lab on the spectral
method.
Commented out several parts of the Pseudospectral lab that the students
have already seen earlier on in the lab manuals.
Some small clarifications to the spectral method lab.
make plotting script consistent

Modify the plotting script to conform with the rest of the labs.
comment out old plots

Also clear figure after each plot.
use relative size for figure

Also removed forced positioning.
updated figure
Merge pull request #19 from ayr0/ian_spectral

Modify plots
Redid spacing and formatting in the heat flow lab.
Initial editing pass on heat flow lab.
Added a description of how to do animations in Matplotlib.
Added tridiagonal algorithm to the heat flow lab.
Also cleaned up various other miscellaneous things.
Added various hints for implementation.
Fixed Error plot to match problem in Heat flow lab.
Typo fixes.
First runthrough of key grammatical editing
Second round of grammatical edits
A few final touch ups
Quick preliminary run-through with spellcheck
First few edits to pandas lab.