The Anything is a collection class implementation which combines the
characteristics of a list and a hashmap into one data structure.
Elements are stored in insertion order and can be accessed by offset position. These elements are of simple types (boolean, number,
string, etc.) or are (recursively) Anythings.
Additionally elements can carry a key (slotname). So Anythings have also hashmap (dictionary)
The implementation also provides methods to read and write Anythings from/to streams and strings. The list
semantics ensure, that Anything slots are written back in the same order as they were inserted/read. This is a very convenient feature for manipulating configuration files or for regression test diff-tools.