Upgrade from 0.2.3 to 0.2.4.

<ChangeLog>

nginx modules:

*) Change: stream module handlers are refactored.

New methods and properties:
s.on(), s.off(), s.allow(), s.done(), s.decline(),
s.deny().

Removed properties of Stream object:
s.OK, s.ABORT, s.AGAIN, s.DECLINED, s.ERROR (replaced
with s.allow(), s.done([code]), s.deny()).

s.buffer (for reading replaced with data argument of
the corresponding callback, for writing use s.send()).

s.fromUpstream (replaced with a callback for a corresponding
event).

s.eof (replaced with flags.last).

Core:

*) Feature: added Function.prototype.length.

*) Feature: introduced sandboxing mode.

*) Improvement: added exception strings where appropriate.

*) Improvement: improved wording for primitive type conversion

exception.

*) Bugfix: throwing TypeError for attempts to change frozen

properties.

*) Bugfix: fixed Object.defineProperty() for existing properties.

*) Bugfix: respecting the enumerable attribute while iterating

by for in.

*) Bugfix: respecting writable attribute for property handlers.

*) Bugfix: fixed exception handling in arguments of a function.

*) Bugfix: fixed Object.prototype.toString for different

value types.

*) Bugfix: fixed Object() constructor for object types arguments.

*) Bugfix: fixed comparison of objects and strings.

*) Bugfix: fixed String.slice() for undefined arguments.

*) Bugfix: miscellaneous additional bugs have been fixed.

</ChangeLog>