(svn r12352) -Fix: Some callback-results were treated as 8 bit, when they were 15 bit, and vice versa.
Var 0x7E procedure-results are always 15 bit.
Callbacks 0x2A, 0x2C, 0x36 (sometimes), 0x39 and 0x145 are 15 bit.
Non-varaction2-calculated callback-results are also affected by the 8bit masking.

Makefile*
bin/*
!bin/data/chars.grf
!bin/data/openttdd.grf
!bin/data/openttdw.grf
!bin/data/opntitle.grf
!bin/scenario/README
!bin/scripts*
config.*
objs/*
src/rev.cpp