Code style
Be consistent about handler names
Update pdf.js
Update README
Make heartbeat, timeout and reconnect configurable

Per server, in environ, as arguments
Make topology compensate for pageOffsets
Update foundation to 5.2.3

- Add Javascript files (might come in handy)
Stub for progress listener
Accept only pdf documents
Correct title
Check if we’re not uploading the same file
Fix minimap offset (relative to height)
Style tweaks
Null check on page
Tweaks