minor updates

xhtml is annoying, srsly
Merge branch 'master' into gh-pages
Merge branch 'gh-pages'
Merge pull request #2 from rupertdance/gh-pages

Merge pull request #1 from rupertdance/master
Merge branch 'master' of https://github.com/rupertdance/100TonnesToLEO
Merge pull request #3 from rupertdance/master

Master