v0.0.4

• Import path can be a function (Christian Lück).
• Correctly parse media queries with more than one item (Christian Lück).
• Add ie_hex_str, abs, min, max functions (Martin Hasoň)
• Ignore expressions inside of calc() (Martin Hasoň)
• Improve operator evaluation (Martin Hasoň)
• Add @content support.
• Misc bug fixes.