Detect needless blank lines

[Ilya-Gh]

Closes #65 as IDEA's formatter is now able to detect blank lines before }.

Please note that additionally to the case described in the issue

fun main() {
    fun a() {
    }
    
}

The rule also prohibits the following construction:

fun a() {

}

and formats it to

fun a() {
}

[shyiko]

Terrific! Thank you, Ilya! 👍