Restore thread if there's no interrupt handler set.

If dispatch is disabled and we don't do this, it'll just hang, never
switching back to a thread that can re-enable dispatch.

Fixes #5172.
Fix savestates from before v0.9.6-536-g62e9e42.

Unfortunately, this breaks savestates made since then until this is
merged.  However, that's only a day or so.

Fixes #5183.
Now umd0: size is in sectors, not bytes.

So we have to check based on that correctly.  Darn it.
Merge pull request #5187 from unknownbrackets/io-fix

Now umd0: size is in sectors, not bytes
Merge pull request #5186 from unknownbrackets/savestates

Fix savestates from before v0.9.6-536-g62e9e42
Merge pull request #5174 from unknownbrackets/intr-fix

Restore thread if there's no interrupt handler set
Oops, only reset MsgDialog result on success.
Validate options in MsgDialog v3 per tests.
Allow msgdialog override of ok/cancel button text.

Per tests, and hints from JPCSP.
Merge pull request #5188 from unknownbrackets/msgdialog

Clean up some more minor things in message dialogs
Shouldn't voice.type == VOICETYPE_VAG/PCM
Merge pull request #5190 from raven02/patch-32

Shouldn't need voice.type == VOICETYPE_VAG/PCM
Revert "Merge pull request #5190 from raven02/patch-32"

This reverts commit aef180259aca86a3bee12dd0668488517a11d69b, reversing
changes made to d69f02dea050e4a6cce55c3c70eb9cd21383b827.
Comment the fallthroughs in SasAudio.cpp
Merge remote-tracking branch 'upstream/master' into fps2