Added box exclusions and improved agent detection

- Automatically selects the Sandboxie agent in use.
  - Restores support for SbieCtrl.exe.
  - Some icons are displayed differently depending on the agent.

- Templates and template settings have been excluded from the box list.

- Improved `explorer.exe` and `regedit.exe` path detection.

- Fixed an issue that caused some menus to be duplicated unnecessarily when in the tray mode.

- Some adjustments have been made to the creation of shortcuts.

- Other minor bug fixes.