Strip down the old event system

This removes unused code, event types, IE pltypes, and event IE types
where possible and makes several functions private that were once
public. This includes a renumbering of the remaining event and IE types
which breaks binary compatibility with previous versions. The last
remaining consumers of the old event system (or parts thereof) are
main/security_events.c, res/res_security_log.c, tests/test_cel.c,
tests/test_event.c, main/cel.c, and the CEL backends.

Review: https://reviewboard.asterisk.org/r/2703/
(closes issue ASTERISK-22139)


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@396887 f38db490-d61c-443f-a65b-d21fe96a405b
Refactor CEL to avoid using the event system core

This removes usage of the event system for CEL backend data
distribution and strips unused pieces out of the event system.

Review: https://reviewboard.asterisk.org/r/2732/


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@396888 f38db490-d61c-443f-a65b-d21fe96a405b
Allow res_parking to be unloadable

This change protects accesses of res_parking such that it can unload
safely once transient uses of its registered functions are complete.
The parking API has been restructured such that its consumers do not
have access to the vtable exposed by the parking provider, but instead
route through stubs to prevent consumers from holding on to function
pointers.

This adds calls to all the parking unload functions and moves
application loading and unloading into functions in
parking_applications.c similar to the rest of the parts of res_parking.

Review: https://reviewboard.asterisk.org/r/2763/
(closes issue ASTERISK-22142)


git-svn-id: http://svn.asterisk.org/svn/asterisk/trunk@396890 f38db490-d61c-443f-a65b-d21fe96a405b