Normalize package.json.
Update dependencies.
Merge pull request #427 from XhmikosR/package.json

Improve package.json and bump dependencies
Update JSHint rules.
Enable JSHint's `indent` rule.
Enable JSHint's `quotmark` rule.
Enable JSHint's `eqeqeq` rule and remove `eqnull`.
Move global config to jshint's configuration.
Remove unused variables.