Twitter Parser Improvements

[dennyabrain]

We rely on parsing the DOM structure to extract structured data out of a tweet. This can break if twitter's DOM structure changes.
an important feature of the parser should be How quickly we can fix it if the twitter dom structure changes. We must identify things that can change at the twitter level and the things that will need to correspondingly change at the parser level. This will help in evaluating various implementation of the parser and ensuring that its easy to maintain.