A4 version

A version for printing on international standard A4 paper.
closed parens in intro
fixing references
fixing references
fixing references
fixing references
fixing references
Merge pull request #284 from dvanduzer/master

Convert mathpartir.sty to UTF-8 encoding
Adjust A4 margins

Adjust the margins of the A4 version so that the width of the
text column is the same as it is for the letter version.
Merge pull request #288 from robinhouston/master

A4 version
Better handling of empty pages for letter and a4
Prerequisites and compilation instructions
Improved README.md installation instructions
Misspellings run

Based on:
  misspellings $(find * -type f \! -name '*.png' \! -name '*.xcf')

This is a tool I use for spell checking source code. I was curious how
it would do on math/tex. Mostly false positives, but the following
three valid hits.
Merge pull request #291 from lyda/mispellings

Misspellings run