Rounding errors in colors

[agar]

Hex values are being rounded at some point to produce slightly different values than those done by less.js.

For example, twitter bootstrap in less.js generates:

.label.notice {
  background-color: #62cffc;
}

where as less.php generates

.label.notice {
  background-color: #62d1fc;
}

[Mordred]

Test my last commit. It should fix this issue.

[agar]

Thanks, all phpunit tests now pass :)