(svn r14611) -Fix (r13437)[FS#2421]: Store the age of a house in the map array instead of the construction year.
Note: Savegames from r13437 to now are broken and have a age of 255 years for a lot houses.

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