Allow loading game info without clearing old.

More seamless when we already have the icon, for example.
Refactor a bit to simplify the code.
Load the icon on the game screen with the bg.

Still looks nicer this way.
Further add a codecType check
Avoid locking up the UI for gamecache loads.

If the icon/bg is not loaded yet, we'd lock and block for it to load
anyway.  This uses a separate (or possibly atomic) lock.
Warning fix.
On main screen, show game bgs using controller.

This won't affect touch UIs but it's a nice touch for controller based
animation imho.
Use flags to specify wanted data in gamecache.
Support PIC0 in PBP files.
Make it easy to get the SND0.AT3 data.
Return error codes in register/release subintr.

This checks for duplicate registrations and other thigns that could've
been causing wrong behavior.
Allow sub interrupts to be enabled before register.

Could've caused interrupts, primarily vblanks, not to run because we
implicitly disabled them on register.
Merge pull request #6387 from sum2012/Atrac-minor

Further add a codecType check
Merge pull request #6388 from unknownbrackets/ui-tweaks

Show game background during controller/keyboard game selection
Merge pull request #6389 from unknownbrackets/intrman

Correct error codes and dup checks in inter registration
Be consistent about how we read and update the UI state variable
GameInfoCache: Clear snd together with bg
Linux buildfix attempt
sceAtrac3 minor cleanup: Get rid of mutable globals, add another sanity check with reporting
Update submodules (lang, native buildfix)