Add code linting using jshint

closes #50
- Add gulp-jshint
- Add jshint-pretty
- Add .jshintrc with ruleset
- OCD: Order devDependencies
- Add new gult lint task
Convert code to comply to .jshintrc and Ghost coding style.
Reactified all .jsx files to .js

closes #52
- Converted .jsx files to bare .js files
- Adjusted gulp lint task
- Allows newcap in jshint
Merge pull request #51 from halfdan/jshint

Add code linting using jshint