Basic Line Forward All Changes and Automated Oncall Script

Added

• Restructured module into a directory structure with one file per function separated per scope, public and private.
• Renamed Set-LineForward to Add-LineForward
• DirectoryCSS now optional in Add-LineForward
• Updated documentation
• This CHANGELOG file
• Added .gitignore
• Same directory precedence, use settings.xml or *.cred in same directory if exists.
• Added Remove-LineForward function to toggle Voicemail forward or remove entire ForwardAll setting.