This patch changes how `Feature`s configs work - they are now required
to use a separate config object (each `Feature` their own class, derived
from `FeatureConfig`) that is to be used as a `perconfigobject` storage.
`Feature`s themselves are not supposed to interact with their config
objects directly, instead using JSON-serializable type, which should
allow us a universal way to change `Feature`'s config variables during
execution.
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.
Anton Tarasenko