Support for Kotlin projects about blade

[FrantisekGazo]

Looks like no update is necessary. This library can be used also in pure Kotlin projects.

Gradle will require to use 2 more plugins for kotlin:

apply plugin: 'kotlin-android'
apply plugin: 'kotlin-kapt'

also kotlin dependency implementation "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version", but most of this will be done by AndroidStudio automatically.

The only problem is that annotated fields have to be public or package-protected which is kind of problematic to achieve in Kotlin. I found 2 ways:

1) lateinit modifier:

@Inject
lateinit var presenter: MyPresenter

This can be used for @Inject or @Arg/@Extra fields, but it's not a good idea for @State.
Primitive types and nullables cannot be assigned with lateinit, which is very limiting.

2) @JvmField annotation:

@State
@JvmField 
var text: String = ""

This can be used for all Blade annotations.
It supports primitive types, nullables and you can also define a default value for the field.
(The only downside is that it makes the field public and not package-protected as I would like.)

If you know any better way for this or have some other questions/problems regarding Blade compatibility with Kotlin, please write it here and I'll open this issue again.