closes#445
- added an fn to sanitize the pathname, that might include a pagination url
- fixed an issue, where the request would still be made if the current page is bigger than max pages
- added comments
closes#321, closes#323
- use `requestAnimationFrame` and related techniques to minimise scroll processing
- add an `isLoading` guard to ensure we don't try to process anything until the next page has been loaded+inserted
- check for a 404 as an indication we've loaded as many pages as possible at which point the scroll behaviour is removed
- sanitize `window.location.pathname` to remove hash params and any double-slashes that may result
- add a 100px buffer from the bottom of the screen so that it's not necessary to exactly hit the bottom before infinite loading is triggered