add data-trunk8-* support

add attribute  data-trunk8-* to each element for special settings
@rviscomi sorry for my english,i am uncertain if i understand your words
<pre>It should not take precedence over the options object in init.</pre>
the order of the config is :
trunk8.defaults -- trunk8 config -- element attribute
 and the next will override the last
This line has gotten to be very long. Could you set attribute.name.substring(trunk8DataAttributeName.length) to a local variable "optionName"?