EMI: Implement screenshot thumbnails for savegames
GRAPHICS: Initialize/Destroy _storedDisplay
EMI: Free materials as soon as they are no longer in use by any costumes.
Merge pull request #954 from chkr-private/savegame-screenshots

EMI: Implement screenshot thumbnails for savegames
Merge pull request #967 from Akz-/emi-fix-savecrash

EMI: Free materials as soon as they are no longer in use by any costumes
EMI: Honor X and Y attributes to spoken lines, rebased from Botje.
EMI: Put the speech text on the top of the bounding box.
GRIM/EMI: Use only the kerned width when determining text width.
EMI: Fix spacing between word wrapped lines.
EMI/GRIM: Fix text position. With the correct height, we don't need to adjust the line height any more.