[Lanterna] Add grep and find commands, ignore unimplemented flags in cp
[Lanterna] Rename GraphicsCommand to AdvancedGUICommand, remove old JavacCommand
[Lanterna] Shell commands: makes cp/mv/rm/mkdir/rmdir closer to standard behavior.
[Lanterna] Add a faster vi implementation using a lower-level graphics API.
[Lanterna] Rename old vi implementation.
[Lanterna] Refactor low-level key events to share and clarify keyPressed/keyReleased/keyTyped logic (7)
[Core] ControlUnit.throwException: add static synchronized case, don't set PC because we only need pcStart
[Core] ControlUnit.runSpecialMethod(): don't check if the current frame is null