Small edits to fft algorithm lab and added a solutions file.
Made changes to shorten the fft algorithm lab.  Added fft labs to Vol2.
Added solution files to both 1d fft labs.
fixed syntax errors and clarify some grammar
more syntax fixes

Apparently, when I edited this lab earlier I probably did an unfortunate
replace all.
reorganized introduction

changed the introduction to focus more on cython being an automation of
writing a C-extension for Python.
edits to typed declarations section of lab

Reword and reorder some of the content for clarity.
center figures
Merge branch 'develop' into fft
changed figure generation in arrays lab to fix the mismatched figures.
regenerated the figure for the arrays lab.
Merge pull request #261 from insertinterestingnamehere/hotfix

fixed plot mismatch in arrays lab.
add missing figure
Merge pull request #262 from ayr0/hotfix-newtonmethod

add missing figure
change python interactive prompt
change interactive prompt symbol

Also removed some legacy labs
change interactive prompt symbol
Merge pull request #263 from ayr0/prompts

Change interactive prompts
Various edits on labs 1 and 2.
Replaced eps files with pdf files for pdflatex compatability on windows.