This is a giga commit, something that should not really be done with
git, but I messed up.
This commit brings a great amount of changes, most important is
reworking `TextAPI` and alsmost complete replacement of `string` with
`Text`/`MutableText`.
Another huge change is introduction of command system that allows to
define commands in a centralized manner, handles auto-parsing of
their parameters and auto generates help info.
Lastly, JSON data types were replaced with new
`DynamicArray`/`AssociativeArray` that are better designed and more
generic.
Refactors `User` to simply store persistent data, while making `APlayer`
represent a connecte playr with appropriate links to `User` and (in
future) his in-game pawn representation.
To avoid needless creation of `APlayerID` classes we need to provide a
separate static method `GetSteamDataFromSteamID64()` that will generate
raw `SteamData` that we can then compare to existing instances of
`APlayerID`.
Anton Tarasenko