ZVISION: Add a hack to set the correct frame delay for RLF videos

Also, use Common::Rational to avoid using floating point math
ZVISION: Remove dead code
ZVISION: Remove duplicate code
VIDEO: Fix check to see if the frame rate is a whole number

Thanks to Marisa-Chan for spotting
SCI: Silence a gcc warning
SCI: added LSL3/German 5 1/4" floppy version
SCI: fix typo in comment for LSL3/German
ZVISION: Plug a memory leak
ZVISION: Disable unused code
ZVISION: Introduce pixel formats for resources (555) and screen (565)
ZVISION: Let the cursor manager do pixel format conversion for cursors
ZVISION: Set all the internal graphics operations to use RGB555 (1/2)

This is the first part of the changes to make the engine use RGB555
internally again. This is done to simplify the rendering pipeline -
the engine will use RGB555 internally, but will output to RGB565.
The overall changes have been broken into two commits, thus this
first commit will break all the game colors
ZVISION: Set all the internal graphics operations to use RGB555 (2/2)

This is the second part of the changes to make the engine use RGB555
internally again. This is done to simplify the rendering pipeline -
the engine will use RGB555 internally, but will output to RGB565.
The overall changes have been broken into two commits, with this
commit finishing all the changes.

This is needed, as the game uses RGB555 graphics internally, but
its AVI animations (full screen and in-game) use RGB565
ZVISION: Plug another memory leak. Some cleanup
ZVISION: Plug more memory leaks
SCI: actor file format, add debug code kPortrait
ZVISION: Document some of the ActionRegion effects
ZVISION: Resolve some TODOs
ZVISION: Fix frame rate for RLF videos and remove hack in AnimationNode

_frameTime refers to msec, not ticks
ZVISION: Remove dead code