virtual hyperscript refactor

- removes data- attribute hack (breaking change)
- fixes for lte ie8 (remove typed error and data-set, use ev-store, use isArray and for in)
- attribute hook takes namespace since attributes can be set directly, otherwise this hook is redundant
- minor refactors (move svg attributes out to a separate file, use semi colons, use strict and single quotes, use `hasOwnProperty` instead of `in`)

//cc @Raynos
casting numbers to strings should be out of scope. What next, casting booleans? casting regexs? casting xyz?

Just use strings for text nodes.