format readme to use markdown, and replace readme.txt
reformat all source code to conform to style conventions

PEP-8 was used as a guide, primarily. This means spaces after commas in
most places, as well as around most arithmetic. The text width was also
adjusted to be 80 in most places. Many TODO comments were also added in
places where there seem to be unused functions or other unnecessary or
unclear code.
readjust readme textwidth and style

The textwidth of some of the embedded code was too large, so it was
causing (ugly) overflows on github. Also, some inline math involving
multiplication was being treated as emphasis, so these, among others,
were surrounded with backticks.
delete old backup files, and all their pattern to gitignore
correct style to conform to PEP-8 in the examples

Mostly done automatically by the autopep8 tool.
Merge branch 'master' of github.com:DomNelson/tracts

A proper merge is not really possible, since the automatic styling of
the files with autopep8 on my end essentially rewrote the files, so git
is unable to figure out where the changes really are anymore (in
considers large swaths of program text to be different between the
branches.) To resolve this, I used the 'ours' merge strategy, and in
this merge commit, applied Dominic's changes by hand in the correct
locations.