Minor clenaups: add jshintrc, lint files, change package.json run scripts

This PR:
+ remove path specification from npm run-scripts: npm does it for you already (thus it will work both on linux/win machines regardless of separator being '/' or '\')
+ add browserify/jscs/jshint as they were used in scripts
+ add dev run script for watchify to run in development
+ add .jshintrc file & lint all the files

Known issues: ATM, `npm run check` will fail with
```bash
> jscs src/

No configuration found. Add a .jscsrc file to your project root or use the -c option.
```
And `ln -s` won't work on windows, probably. There're other ways to extend `require` path searched, but I cannot through in any at this time of the day, sorry.