Switch to std::function for savestate callbacks.
Save state to a temp file and rename.

This way, if you run out of disk or hit a bug, at least you have your old
state.  Better than having neither.
Take screenshots with savestates.
Just leave Symbian the way it was.
Oops, ignore DX9 on non-Windows.

This probably had broken Qt before, whoops.
Try default constructors for Symbian.
Merge pull request #7203 from unknownbrackets/savestates

Create savestates to temp files for safety