Merge pull request #1 from spratt/master

Update
Thirty days hath ... April.
Merge pull request #2 from psimonyi/master

There is no April 31st.
make it vim-friendly
Clarify regular and honourary membership
selection of first-year directors (and cleanup)
Clarify amending formula

Importantly, the threshold for passing an amendment is half of
those present at the general meeting.
Portfolios are held by directors-at-large
Chair of the Board and backup
Signing authority is two people
Automatic repeal of "extenuating circumstances"
Correct name of the society and rephrase its intro
Membership levels, Chair without Secretary
Directorship selection
fix two typos
Update draft/bylaw1.tex
Merge pull request #2 from jcampbe/patch-2

Shorter, clearer definition of a CS student.
Merge pull request #3 from psimonyi/master

It still may need some typographical changes, but every substantive change looks good.