dillon1000/react

style prop improvements

Some improvements to how style={{x:y}} is handled in React:
* ignores null styles, rather than setting them.

Codez:

    var highlighted = false;
    <div style={{color: highlighted ? 'red' : null}} />

Before:

    <div style="color:;"></div>

After:

    <div></div>

Respects that 0 has no units.