Underscore in some rules

[Daniel Ruf]

I saw some _ in property names.

https://raw.githubusercontent.com/tachyons-css/tachyons/master/css/tachyons.min.css

Why are they there?

[Daniel Ruf]

2fd4052

Shouldn't these be removed? Because float always results in block.

Also see http://www.w3.org/TR/CSS2/visuren.html#float-position

[Cristiano Fromagio]

See #480

[Daniel Ruf]

The \9 property suffix is meant to target IE8 and below, the * prefix targets IE7 and below and _ prefix targets IE6 only.

I don't think we still have to support these.

[Adam Morse]

@DanielRuf No negative impact to support legacy browsers here