Characters Counter

+ Added  jQuery Textarea Characters Counter Plugin support
+ Added initia Greet Form package (in future — auxiliary utilities for some forms elements)
+ Enabled Characters Counter Plugin in `<gleez>/contact` page

I used [HTML5 data-* Attributes](http://api.jquery.com/data/#data-html5) for passing parameters to `Greet Form` which, in turn, calls ` Characters Counter` with the chosen parameters from  data-* attribute

Configuration as usual — `config/contact`.  In this regard nothing is changed. 
`@todo`: Need to add a visual setting to admin dashboard.

@sandeepone This draft. But it works. You should pay attention to it. Maybe you can make it more versatile.