(svn r13619) -Codechange: use 'const char *' instead of std::string for blitter and driver names
Removes indirect dependency on <string> for 20 files, reduces binary size by 16kB

(svn r13618) -Codechange: move tar-specific declarations to separate file
Removes indirect dependency on <string> and <map> for over 40 files

(svn r13617) -Codechange: calculate the diff in StationWaitingSorter directly

(svn r13616) [NoAI] -Fix: on AIAbstractList->Clear(), make sure the sorter is invalidated too

(svn r13615) [NoAI] -Fix: fixed most, if not all, problems around AIAbstractList. It is now safe to remove values while looping, among other things.
[NoAI] -Add: allow foreach() usage for AIAbstractList
[NoAI] -Add: allow [] usage for AIAbstractList (read-only)
[NoAI] -Add: allow [] usage for AIList (read/write)

(svn r13614) [NoAI] -Add: AIGroup which allows an AI to manage its vehicle in the context of groups.

(svn r13613) [NoAI] -Add: added AIStation::GetNearestTown(), which returns the nearest town AT MOMENT OF STATION CREATION (Yexo)

(svn r13612) -Fix [FS#2104]: wrong comment of CmdSetAutoReplace. Patch by Yexo.

(svn r13611) -Fix [FS#2100]: if the first bridge can't be build for a given length, then none of the other bridges can. Effectively meaning that if someone replaces the first bridge with a bridge that can be only 3 tiles longs then only other bridges that can be 3 tiles long will be buildable, but only if they are 3 tiles long.

(svn r13610) [NoAI] -Add: AIDepotList giving you a list of the locations of your depots (including hangars).