(svn r23525) -Codechange: make Window::flags4 WindowFlags instead of uint16, with only values known in WindowFlags (and move out 2 timers to their own variable)
-Codechange: rename Window::flags4 to Window::flags
-Codechange: move some non-inline functions from .hpp to .cpp

(svn r20453) -Codechange: Remove direct accesses to Window::hscroll, vscroll and vscroll2.
Note: All windows get individual members with the same names, which are initialised via Window::GetScrollbar(). This caching is not required at all, but simplifies conversion.

(svn r18195) -Codechange: move the child padding calculation/handling to WWT_FRAME
-Fix (r18168): crash when switching languages when a non-standard font height is used

(svn r18045) -Fix: GCC 4.5@HEAD not compiling OpenTTD anymore because of a "non-placement deallocation function [is] selected for placement delete", or in other words delete(void *, size_t) is 'magic'.
We implemented these delete(void *, size_t) operator functions because MSVC warned that "no matching operator delete found; memory will not be freed if initialization throws an exception" for new(size_t, size_t).
This disables MSVC warning about this because we do not use exceptions in the (constructors that use the) overridden allocation functions, as such they will never be called; delete(void *) remains necessary though.