(svn r17897) -Fix [FS#3255]: CB15 and CB36 (capacity) were not always called when they should.
-Codechange: Move capacity calculation to a single function for all vehicle types, so the behaviour can be kept consistent easier.

(svn r17758) -Revert (r17208): Use assert_compile() if you cannot count.
-Fix (r7326): Powernaut Helicopter got wrong 'load amount'.
-Fix (r2639): Call the Evil by its name.

(svn r15541) -Revert (r15399): 'v->cargo_type' is also used in other places, which cannot accept CT_INVALID.
-Codechange: Add Engine::GetDefaultCargoType() and Engine::CanCarryCargo() and use them.
-Fix [FS#2617]: When articulated parts have no available default cargo, use the cargo type of the first part for livery selection.
-Change: To decide whether a vehicle is refittable do not test its current capacity for being zero, but always use the 'capacity property'.
Note: The property is used unmodifed without calling CB 15/36. By setting it to a non-zero value and returning zero in the callback vehicles can be refitted to/from zero capacity for e.g. livery effects.
Note: It is intentional that you cannot control refittability by CB 36.

(svn r15077) -Codechange: enumify DAYS_IN_YEAR and DAYS_IN_LEAP_YEAR
-Change: when computing daily running cost, divide by 365 (instead of 364). Since r12134, the rounding errors don't need this correction anymore

(svn r15027) -Merge: tomatos and bananas left to be, here is NoAI for all to see.
NoAI is an API (a framework) to build your own AIs in. See:
http://wiki.openttd.org/wiki/index.php/AI:Main_Page
With many thanks to:
- glx and Rubidium for their syncing, feedback and hard work
- Yexo for his feedback, patches, and AIs which tested the system very deep
- Morloth for his feedback and patches
- TJIP for hosting a challenge which kept NoAI on track
- All AI authors for testing our AI API, and all other people who helped in one way or another
-Remove: all old AIs and their cheats/hacks

(svn r14958) -Codechange [FS#1923]: when checking for unique names, compare only with manually set names
There are situations that aren't solvable (because of different language files), so if the user really wants to have duplicated name, allow him to do so. It solves desyncs between server and clients using different languages. It behaves the same in SP and MP, so users won't see the different behaviour as a bug (and even checking in SP could be worked around by the user).

(svn r14735) -Codechange: remove a bit of bit-waste in the map array (without changing the map array) and make the CompanyIDs contiguous.
-Note: 15 should be enough for now... making it any more means adding more bytes to the map array and thus wasting more bits instead of reducing the bit waste.