Merge pull request #5 from stevenbedrick/master

Added __init__.py so that we can easily import textgrid.
Updated header and added .gitignore
Added header stuff and .gitignore
Merge branch 'master' of https://github.com/kylebgorman/textgrid
Multiline text field support

TextGrid._getMark is now robust to multiline text fields. That doesn't
mean you should use them, just that it can handle them if they come up.