Adding a custom folder for custom checks

This will be a place for user defined Chromedriver scripts to
periodically run on the loaded pages. Adding a readme to reserve the
path even though we will gitignore files in here.
Ignoring the user defined Python in custom folder
Adding config options for custom checks

Setting up the ability to do custom checking within the watcher process.
Adding custom check function
Merge branch 'checks'

Conflicts:
	browser.py
	init.py