Adding the new chunked file format (CFF) system.
Making wtf.db.load async and fixing the async load flow.
This makes node.js apps work again, though with some modifications to
their load flow. Also adding a mock Blob object for node to get things
working there.

This removes the wtf-json and wtf-calls support, for now.
Cleaning up the loading code to allow for saving without storing data.
Only snapshots require keeping a Blob around, which smart browsers can
page out. Others (URLs/Drive files/etc) are stored by reference and
redownloaded as needed. This helps save address space on 32-bit systems.