ES2015 complient import structure

[johanlahti]

Our current import style is based on the old-style "globals". In our case, we prevent from polluting the global namespace by binding everything to only one global variable, smap. There are smarter ways of managing libraries, such as…

• CommonJS standard (like in current Node.js)
• Asynchronous Module Definition (AMD) ( like in RequireJS )
• EcmaScript 2015 (ES2015)

…where the latter is preferred, because it's a new JS standard and supports both sync and async imports.

Many libraries are today distributed supporting one, or all, of these import styles.

As a start, we should adapt our building script to at least support ES2015 in the plugins. This enables us to use the rest of the ES2015 features.

[johanlahti]

New gulp tasks implemented using webpack, which enables the features described in previous comment.

gulp watch:js  // -> Watches for changes in plugins' JS files and transpiles from ES2015 to ES5 using webpack (outputs to dist folder)
gulp ourjs    // -> Transpiles all plugins to ES5 and then merges with core's js