#58 CQuery: internal state should be invisible

Internal source list/array/collection should not be exposed by #list #set or #array methods.

#sort and #reverse method should not have impact on source collections too.

We should implement this using SharedList

Może zamiast zabawy w SharedList powinniśmy po prostu dodać metody: listview() i tyle?

sort - OK

we should implement copy-on-write list/set

copy-on-write list is implemented.

methods reviewed:

• list returns CopyList or new list.
• set returns new set
• array returns always new array (cloned)
• sort returns new list
• reverse returns reversed read-only list.