Function name now consists of 3 parts:
1) full package path
2) method receiver type (if any)
3) function name itself .
Fix#1150.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Invoke `_initialize` method on every call if present.
In NEO3 there is no entrypoint and methods are invoked by offset,
thus `Main` function is no longer required.
We still have special `Main` method in tests to simplify them.
Before introducing slots it was hard to change global variables
preserving changes across multiple function calls.
This commit implements such possibility.
Closes#638.
