`AssociativeArray` by design does not manage keys, automatically
deallocating them, like it can with stored values. This patch adds a
parameter to `Empty()` method that allows it to deallocate all of the
used keys when deallocation all of the values.
As a side effect this patch also fixes a bug that broke
`AssociativeArray` after using `Empty()` method.
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.