Allowing alerts to accept icons before text.

One more parameter to pass:

// This will render a question point before text:
ohSnap('glyphicon glyphicon-question-sign', 'Oh Snap! I cannot process your card...', 'red');

// No icon to show, just pass '' or null:
ohSnap('', 'Oh Snap! I cannot process your card...', 'red');
Merge pull request #2 from Torone/patch-1

Allowing alerts to accept icons before text.