v2.4.0

• When minifying floating points, remove trailing zeros and not other numbers
• Make M concurrent-safe
• HTML: keep double quotes around XML-flavour RDFa attributes
• CSS: revert the use of the #RRGGBBAA format as proposed in Color Module Level 4 as it is not yet an official W3C recommendation
• CSS: background-position (also within background) now works with 3 and 4 values as well
• SVG: skipping metadata or rect tags properly even if they are closed by a void tag (like <rect/>)
• SVG pathdata: when cursor doesn't move, don't emit any commands