Merge getline.ts and frontend changes

[q3k]

This introduces the following from the tsfrontend branch:

• symbol(), name() and decimals() getters for Token class in getline.ts
• humanize() and integerize() helps for Token class in getline.ts
• yarn build fix in frontend by supporting ES6 for minification

[q3k]

And you're right about interestPermil. Please file a bug, I'll change this later.