Remove class from Javac on delete/rename file

[trett]

• Removing class from Javac on delete file event by calling inner methods syms.removeClass(...) and chk.removeCompiled(...)
• All references on deleted class are linting after being removed
• Fixed the dynamic registration for capabilities.

[georgewfraser]

This is a complex PR, sorry it has taken me so long to merge @trett . If you can split it into a separate PR for the dynamic regristration bit, that will make it easier for me to merge, but regardless I will get to it eventually.

[trett]

Yes, sure. I've opened two separate PR's #262 #263