Fix whitespaces and quotes in Gruntfile.js
Add gulp and gulp-util to devDependencies in package.json
Add basic gulpfile.js
Port "generateChrome" Grunt task to gulp

Add the following gulp tasks:
- js - lint and copy js to build/chrome/results/
- css - copy source/common/css to build/chrome/results/css
- templates - compile Handlebars templates
- vendor - copy source/components to build/chrome/results/components
- chrome-manifest - generate manifest.json in build/chrome/results

These are temporary ports for compatibility with current code.
See discussion: #18.
Use gulp-run-sequence to control build flow

Return stream from every async task to know when it finishes.
In "default" task use sequence to run "chrome-manifest" after others.

Also use callback in "default" task to know when it finishes.
This is good for upcoming "dist" task which will depend on "default".
Add "clean" task which cleans build/chrome/results before build
Move "fs" module to basic group in gulpfile.js
Add "dist" task which packs chromium extension zipball

This faces #24.
Update README.md: offer single *-chromium.zip instead of Chrome / Opera

This closes #24.
Finally transition to gulp

- remove Gruntfile.js
- remove "grunt" and others from devPedendencies
- remove source/templates/.gitignore - ignored temp Grunt file
- use gulp on Travis CI
Add "watch" task performing "default" task on changes

This closes #18 as Grunt is fully replaced with gulp.