remove repeated entypo icons
add sandbox page
add inline comments to src/css/mixin.less
comment out data-sending piece of google analytics to prevent spurrious data from being sent to janux.org account
Integrate improvements from cucina project, and more, including:

- add responsive.less file for the responsive section
- add gulp/scripts.js and .jshintrc for js linting, and add section to copy js files to dist
- use node.js 'config' package to parametrize build
- move config sections of various gulp/*.js files to config/default.js
- remove superflous janux_logo_256.png (use janux-logo-256.png instead)
move config of gulp/watch.js to config/default.js