Change: Use bitmap for free unit ID generation. (#12165)

This improves performance of finding the next free unit number for a vehicle.

Based loosely on pool's used slot bitmap.

Codechange: Store Colours in Colours type. (#11625)

This reduces casts, some magic numbers, and introduces a bit of type-safety.

Codechange: Using alias and std::array for company expense storage. (#11273)

This simplifies passing yearly expenses to functions and use of std algorithms.

Codechange: automatic adding of _t to (u)int types, and WChar to char32_t

for i in `find src -type f|grep -v 3rdparty/fmt|grep -v 3rdparty/catch2|grep -v 3rdparty/opengl|grep -v stdafx.h`; do sed 's/uint16& /uint16 \&/g;s/int8\([ >*),;[]\)/int8_t\1/g;s/int16\([ >*),;[]\)/int16_t\1/g;s/int32\([ >*),;[]\)/int32_t\1/g;s/int64\([ >*),;[]\)/int64_t\1/g;s/ uint32(/ uint32_t(/g;s/_uint8_t/_uint8/;s/Uint8_t/Uint8/;s/ft_int64_t/ft_int64/g;s/uint64$/uint64_t/;s/WChar/char32_t/g;s/char32_t char32_t/char32_t WChar/' -i $i; done

Feature: allow to do a hostile takeover of an AI company (in singleplayer) (#10914)

With the removal of the share-system, you could no longer make an
AI disappear in a single player game. At least, not without going
into the console.

Codechange: Base CargoArray off std::array.

This avoids needing to define array accessors and allows use of
default value initialization.

Change: include fmt.h C++ headers in stdafx.h

This to prevent compilation issues between runs with and without precompiled
headers. Also remove the headers from the rest of the code base as they are
not needed there anymore, although they do relatively little harm.

Change: replace per-AI "start_date" with a global "competitors_interval" (#10653)

The per-AI "start_date" is a lot of custom code, and was rarely
used in the way it was meant.

While at it, also ported this part over to the new timer system.

Fix: Company values do not properly account for shares (#9770)

Co-authored-by: Charles Pigott <charlespigott@googlemail.com>

(svn r17058) -Codechange: magic numbers removal.
Two values used intead of just one, as it gives more possibilities to those who dare...

(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 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.