Precondition on active process title

Changelogs:

1. Add ability to add task precondition on active window title & active process name. On Mac this is active application.
   Note that on Mac this feature (active window) requires enabling "System Preferences -> Security & Privacy -> Automation -> Privacy tab -> System Events" for the terminal/Java that runs Repeat.
2. Add UI utilities to print out active window titles & process name, as well as mouse positions.
3. Show on main UI whether a task group is disabled to avoid confusion.
4. Fix an old bug that causes error when the directory path has space in it.
5. Remove vestiges of unused JNativeHook library and unused Scala related code and libraries since Scala hasn't been supported for more than a year. This reduces the binary size by a few MBs.
6. Fix some other small bugs.