OO: added inheritance, Collection, Iterator, Iterable, Array. Range is rewritten to be Iterable. Math namespace is temporarily broken (to be updated to new ObjClass model).

docs/Iterable.md

@@ -0,0 +1,31 @@
+# Iterable interface
+
+The inteface which requires iterator to be implemented:
+
+    fun iterator(): Iterator
+
+Iterator itself is a simple interface that should provide only to method:
+
+    interface Iterable {
+        fun hasNext(): Bool
+        fun next(): Obj
+    }
+
+Just remember at this stage typed declarations are not yet supported.
+
+Having `Iterable` in base classes allows to use it in for loop. Also, each `Iterable` has some utility functions available:
+
+## toList()
+
+Creates a list by iterating to the end. So, the Iterator should be finite to be used with it.
+
+## Included in interfaces:
+
+- Collection, Array, [List]
+
+## Implemented in classes:
+
+- [List], [Range]
+
+[List]: List.md
+[Range]: Range.md