added moon transits calculations

[JWebCoder]

I've added the possibility to calculate the moon transits.

var transits = suncalc.moonTransit(moonrise, moonset, lat, lng);

transits will be equal to an object like: {main: {date}, invert: {date}}

The quantity of differences are because i've executed a little bit of jslint agains the file.

[mourner]

Can you bring back the original formatting? I don't see the actual diff.

[JWebCoder]

I've restored the original format.

[Hypnos3]

published a new version which include this as https://github.com/Hypnos3/suncalc3