(svn r8350) -Codechange: [Graphs] Use DrawStringCentered instead of a hardcoded offset to make the string appear centred.

(svn r8349) -Codechange: replaced CMD_REFIT_VEH() and similar defines with real static inline functions

(svn r8347) -Codechange: [Graphs] Make some more variables local to the loops they're used in, and remove some assumptions about the size of an array.

(svn r8343) -Cleanup: [build vehicle windows] added a few comments and removed two switch-cases, that we can do without

(svn r8341) -Codechange (r8336): added assert to VehTypeToIndex() to ensure valid vehicle types in the argument

(svn r8340) -Cleanup (r8338): removed now unused header includes from roadveh_gui.cpp

(svn r8339) -Fix(r8331): MSVC seems to be a little more strict (or less intelligent) then other compilers when it comes to operator precedence.
A copy of code from train_gui.cpp to build_vehicle_gui.cpp was not exactly the same.
The earlier version did not require parenthesis to specify correct operator precedence.

(svn r8338) -Codechange: merged road vehicle build window into the other ones
Note: now all build vehicle windows are merged into build_vehicle_gui.cpp

(svn r8337) -Cleanup: removed some more switch-cases in build_vehicle_gui.cpp and added arrays + VehTypeToIndex() instead

(svn r8336) -Codechange: added function to translate vehicle types to 0,1,2... for use for index to arrays
Used this function to get rid of some switch-cases in build_vehicle_gui.cpp
-Fix (r8335): ship build window didn't remember assending/decending sort setting