v1.0.2 - the shutdown option no longer cuts a batch short

Important fix: "Shut down the PC when finished"

If you used that option with more than one video in the queue, the machine
switched itself off after the first finished file and the rest of the batch
never ran. This build fixes it.

What was wrong: the window hands the converter one file at a time, and the
option was passed into every one of those calls. Each converter then did what
it was told at the end of its batch — which was a single file.

How it works now: the window decides. The PC is only switched off when

• every area is finished — converting, splitting, joining and the watched folder,
• no folder is being watched (a standing order never really ends),
• and nothing is converting outside this window either, e.g. NVENCForge.exe
  started by hand — the process list is checked before anything happens,
• and the batch was not stopped by hand.

Windows performs the shutdown and gives you a minute. On top of its own warning,
the window now shows a countdown with a cancel button (shutdown /a still
works too). The box can be ticked or cleared at any time, including in the
middle of a batch — the decision is only made at the end. Stopping an area
clears it; skipping a single file does not.

Nothing else changed: same converter, same output, same settings.