Remove commented out code in api.js
WIP - more cleanup of global variables
WIP - double request size on each failed attempt to get xref
WIP - clean up optimization for request size for getting xref
WIP - reorder code to cache xhr data
WIP - fix bug with error callback of xhr
WIP - make old full file codepath for addon work
WIP - migrate chunked_ext branch (for ff ext)
WIP - remove a number of breakpoints no longer needed
WIP - fix bug w/ fetching range for addon
WIP - cancel pending xhr requests from addon on unload
WIP - fix bug so that omg, it finally somewhat works for addon