Code/Project Cleanup

Many warnings suppressed:
- 'SubtitleSource.cs' excluded from "Light" build
- Replaced many instances of deprecated member vars with
recommended ones
- Scrubbed extra PropertyGroup 'Microsoft.Common.Props' from
'RS TV Show Tracker.csproj'
- Added 'WPFToolkit.Extended.dll' in '/Dependencies'
- Third-party DLL's copied to '$TargetDir'\libs in build events
settings

TODO:
- Update .gitignore to include 'Settings.json' file
- Copy default 'Settings.json' file to '$TargetDir'
- Copy default 'conf' file to '$TargetDir/db'
- copy default 'library' file to '$TargetDir/misc'
- Suppress Compiler Warning (level 2) CS0618
- Suppress Compiler Warning (level 3) CS0067
- Configure 'Debug' profile