Property change listener efficiency changes

-   Using direct non-enumerable `__` prefixed properties instead of weak
    maps for fast access to change listener records and overridden
    property descriptors.
-   Method names and reusable active dispatch array now kept in book
    keeping to avoid recomputation.
-   Presumed hot dispatch loop factored into separate method to isolate
    from try/catch deoptimization.
-   Removed support for uninstalling property change listeners.
Add toJSON method to collections
Merge effeciency changes for change listeners
Merge pull request #87

For toJSON methods
Implement deleteAll
Update change log
Revert support for wildcard find{,Last} in List

For reasons not yet isolated, this causes the FRB tests to execute at
half speed, perhaps related to map change listeners which still employ a
List.
1.2.0
1.2.1