Removing unused '_msgReceivedCount', some reformatting, and adding a history processor callback for the progress bar.
Add callbacks to send updates on domain progress and speed up history processing by agreggating processed items on the main thread.
Only query new history visits on startup.
Adding 'let' to get rid of warnings.
Show progress based on number of titles processed instead of number of domains.
Load payload as a json file instead of script for faster loading.
Merge pull request #17 from matthewruttley/progress-changes

Progress changes