Replace HTML tags in labels with whitespace

This is the right thing to do for tags such as <br> and <p> and won't
break cases like "text text <b>bold text</b> text" but won't do the
right thing for strange cases like "notbold<b>bold</b>notbold"...
Round decimals with more than 4 places in X labels
Add Yes/No (localized) labels
Merge pull request #40 from scjody/summary-graphs

Graph fixes to labels