Private superclass properties may not be back-in-time debuggable in certain conditions

[kitakkun]

As I described in #89, private properties in superclasses may not be back-in-time debuggable.

For example,

@BackInTime
open class A {
    private var prop: Int = 0
}

@BackInTime
class B {
    var prop: Int = 0 // this is valid because B can't see A.prop
}

In this case, the back-in-time-compiler generates the method for class B like below:

@BackInTime
class B : BackInTimeDebuggable {
    var prop: Int = 0 // this is valid because B can't see A.prop

    override fun forceSetValue(propertyName: String, value: Any?) {
        when (propertyName) {
            "prop" -> prop = value
            else -> super.forceSetValue(propertyName, value)
        }
    }
}

So, logically we can't rewind the state of the prop in class A via class B.
We need to investigate if this problem exists or not, and then fix this potential issue.

[kitakkun]

To fix this problem, we need to add classFqName to each methods declared in BackInTimeDebuggable interface.

[kitakkun]

As I examined in this commit, the expected problem has been confirmed.

So, I renamed propertyName to propertyFqName which contains the parent class's full-qualified name, and then fixed the internal compiler logic in #96.

Now this problem should be fixed.