window.history.replaceState() might not exist

re #19

window.history.replaceState() might not exist in some clients. (amazon fireOS?)

TODO: if doesn't exist, should we do something else?  right now, nothing in history

I also added a few comments, since I hadn't read the JS file in a while.
meteor/startup.js reload update

re #17 

`Reload._onMigrate` added as a "newer" method of registering callback on hot code reload

`Meteor._reload.onMigrate` is deprecated (but should still be supported)

https://github.com/meteor/meteor/blob/d477c8d03bb078f7e8e85dbe4b51db7ae5689573/packages/reload/deprecated.js

(also flipped the logic to fail faster, so the function is easier to read)
use variable already set for URL
Changed zepto ajax to javascript xmlhttprequest and moved success and error callbacks to properties in the MeteorRider object.
make current path a MeteorRider property so we can use it on the onSuccess property
use native javascript to call events.
remove todo comment
fix meteorUrl not being defined when object MeteorRider is defined
meteorUrl can now be referenced inside the onSuccess callback
Merge pull request #20 from DanyHunter/master

use variable already set for URL and remove whitespace.
significant update after PR #20, readme
slight readme update
Huge refactor (v1) +localStorage

* split all MeteorRider functionality into atomic functions
* added tons of commenting and logging
* added localStorage cache of Requested pages (FTW!)
* allowed for simpler config setup (any: url, config, __MeteorRiderConfig__)
* updated the Readme
* setup a MeteorRiderExample0 project
* removed the phonegapapp: not needed, overly complicated, opinionated
* removed zeptojs (wasn't used anymore)
removed experimental file
readme
added missing semicolon in replaceHistoryState()
Merge pull request #22 from Elfoslav/patch-1

added missing semicolon in replaceHistoryState()
Update README.md
fixed reloading on hot pushes
Merge pull request #24 from mstn/master

fixed reloading on hot pushes