Added more conversion methods from primitive types (`bool`, `byte`,
`int`, `float`) into `Text` and `MutableText` into the standart
`TextAPI`. Made `JSONAPI` use these methods instead.
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