StoreBinding.sub now can subscribe to other StoreBindings

Middleware pattern is used
`fn` is called with (err, data, next) arguments
when last `next` in queue is called — original handler would be called.
if you want to change `err` and `data` — call next with two arguments (newErr, newData)

Quality of life feature for DOM: if second argument is not an object — it is treated as children

Math.random.seeded.rand — random from Array items or between two values
Math.random.seeded.constructor now returns a constructor that can create an independent seeded random instance

 Ajax. small fix. Bug in Setting Headers

Arrays can have indexes. ArrayStore instance .index({'ID': true, 'reverseID': true})

DOM
Export as node.js module (for backend usage. great with simplest-dom)

Test Promise feature

Fix Store bug: function subscribed to multiple bind values was called with incorrect arguments. Added test case for it.

added test for it

DOM: more complex recursive events
Store: Working Store.Value.Array binding