* ia/ssl/max-sessions/OTP-12392:
  ssl: Fix documentation mistakes
  ssl: Add upper limit for session cache
  ssl: Measure elapsed time with erlang:monotonic_time

Conflicts:
	OTP_VERSION
	erts/doc/src/notes.xml
	erts/vsn.mk
	lib/kernel/doc/src/notes.xml
	lib/kernel/src/kernel.appup.src
	lib/kernel/vsn.mk
	lib/ssl/doc/src/notes.xml
	lib/ssl/src/ssl.appup.src
	lib/ssl/src/ssl_cipher.erl
	lib/ssl/vsn.mk
	otp_versions.table

If upper limit is reached invalidate the current cache entries, e.i the session
lifetime is the max time a session will be keept, but it may be invalidated
earlier if the max limit for the table is reached. This will keep the ssl
manager process well behaved, not exhusting memeory. Invalidating the entries
will incrementally empty the cache to make room for fresh sessions entries.

Add possibility to downgrade an SSL/TLS connection to a tcp connection,
and give back the socket control to a user process.

Add application setting to be able to change fatal alert shutdown
timeout, also shorten the  default timeout. The fatal alert timeout is
the number of milliseconds between sending of a fatal alert and
closing the connection. Waiting a little while improves the
peers chances to properly receiving the alert so it may
shutdown gracefully.