possible to specify options via data- attributes

Hi, it seems that jquery.find returns an array instead of a single element. This prevented textillate from reading the options specified in the \<li\> elements.

This patch fixes that error. Also, it converts "true"/"false" to true/false in the case of data-in-shuffle etc., and handles situation where data-in-delayScale is forcibly changed to lower case. This makes it possible to specify those options as well.
I would be better to move stringToBoolean to the top level scope (the same as isInEffect/isOutEffect ) so it isn't being continuously redefined.