Integrating the following improvements to the treeview

[bcopy]

Hello,

This pull request includes :

• Support for smilton's extendable HTML elements (add "data-xxx" JSON properties to your nodes, and they get reflected as a data-xxx attribute on the corresponding LI element)
• Support for aguyawry's title attribute
• A fix for expose FindNodes method through the TreeView proxy ( issue #103 )

[toni-moreno]

+1