Add config for jshint
Stop warning: Missing semicolon
Stop warning: 'advanced' is already defined.
Stop warning: a reserved word

- Expected an identifier and instead saw 'in' (a reserved word).
Stop warning: Use '!==' to compare with 'null'.
Stop warning: expression

- Expected an assignment or function call and instead saw an expression.
Stop waring: Missing '()' invoking a constructor.
Stop warning: ['test'] is better written in dot notation.
Add jshist as a node module
Use jshint after test passed
Check unused variables
Update .jshintrc
Merge branch 'jshint'