added underscore.string to use startsWith

[jaeh]

No description provided.

[phaer]

I really thought underscore would include .startsWith(), but no. By design, i think babel should add it to the prototype, because it's in es6 according to MDN.

I am not sure if should add an extra dependency just for one single function which is already included in the language we are targeting. Should we add a babel.transform? Or patch it in ourselves? If we ignore the position argument for now it'd just be

String.prototype.startsWith = String.prototype.startsWith || function startsWith(search) {
  return this.indexOf(search) === 0;
}

right?

[jaeh]

i looked into this,
babel is not including the ecmascript 5 to 3 polyfills by default.

all in all this bloats a prebuilt inlined html file to around 700k,
compared to 371k without polyfill.

since we are running locally i would not worry about that, we might want to cherrypick those we need later though

file inclusion is in the first line of src/main.js, the path is terrible, but it keeps us from having babel as additional dependency.

[phaer]

Which ECMAScript 5 to 3 polyfills? According to the MDN link posted above, String.prototype.startsWith is only introduced with ES 6.

Anyway, I think the easiest solution for now would be to add our own 1-3 line polyfill.