Implement a prototype of BBM.fn.toHTML()

- Remove forward slash from __.escapeATTR(str); Too aggressive
  and hampers readability badly.

- Modified BBM.fn.attr() to return the attribute object with
  zero arguments.

- Some work left to do in BBM.fn.toHTML(), such as indentation,
  and options, like XHTML-compliant output or stripping line breaks
  from text.