(svn r3108) Confine the use of SPR_OPENTTD_BASE to table/sprites.h by adding/using some sprite enums

(svn r3107) -NewGRF: Move train y-position offset adjustment to remove code duplication, and make it apply only to vehicles with a custom image.

(svn r3106) -Autoreplace feature: Continue to show old vehicles in replace window after all player's vehicles of that type have been replaced. This allows the replacement to be removed. These vehicles are shown in grey instead of the player's colour.

(svn r3105) readded 2 line that should not have been removed in last commit(3104). Now cargo are removed when refitting (like it should)

(svn r3104) -Codechange: [refit] removed now obsolite code that the old autoreplace needed

(svn r3103) - Fix: [ 1339000 ] Fix: strgen and plural forms fatal error for untranslated strings. (glx). Also output the correct lines for these warnings, for missing strings the lines correspond with the ones in english.txt

(svn r3102) - Fix (regression): Newly added sprite had problems when newgrf's where loaded. Thanks Tron for explaining what the problem was and how it should be solved.

(svn r3101) -Codechange: added _new_vehicle_id
this var works like _new_train_id and the rest of that kind of vars, except it is set each time a vehicle is build, nomatter what type
this is a nice tool to code vehicle independent code, which in turn can reduce code duplication
Right now it's used in ReplaceVehicle() and CmdCloneVehicle()

(svn r3100) -Codechange [Clone vehicles] Major change to clone vehicles
removed duplicated code and added DoCommand, which used the define build commands added with autoreplace
This should not affect gameplay at all

(svn r3099) Copy&pasto in r3098