2014 week 45

## Javascript linter

## Todo
[x] New task `gulp lint`added.
[x] We should run the above command before every commit.
[x] Karma configuration update: Local tdd will spawn `Chrome` & `Firefox`. Previously it was only firefox.

### JShint configuration
- We should use camel case for variables or functions.
- Report error if used variable is not defined.
- Report if variables declared hasn't been used.