- support PictOpSrc, mask is ignored so far
- support PictOpOver with non-solid source, with or without mask - now QT3
  icons are rendered properly
- move render operations into their own file
missed one
( move CG14Comp_Over32Solid() too )
Fix out-of-range comparison.

clang complained:
warning: comparison of constant 768614336404564650 with expression
of type 'CARD32' (aka 'unsigned int') is always true
[-Wtautological-constant-out-of-range-compare]
Decrease comparison range to avoid tautologies.
(int32 is always smaller than int64_max, even if the latter is shifted 2 bits)
Fix unsigned vs. signed char warnings (needed for clang).
Fix a comparison of constant warning with clang

From upstream:
commit 9acc14c34a372b54f9075ec3611588298fb2a501
Author: Akira TAGOH <akira@tagoh.org>
Date:   Wed Jun 26 12:03:38 2013 +0900
Remove check that can never be true.

clang warns:
warning: comparison of constant 268435455 with expression of type
'CARD16' (aka 'unsigned short') is always false

Sent upstream, will probably be merged soon.
Use correct format string.
Improvements to format strings from upstream.
Use proper format string.