async_wrap/timers: remove Add/RemoveAsyncListener

The ability to add/remove an AsyncListener to an object after its
creation was an artifact of trying to get AL working with the domain
module. Now that is no longer necessary and other features are going to
be implemented that would be affected by this functionality. So the code
will be removed for now to simplify the implementation process.

In the future this code will likely be reintroduced, but after some
other more important matters have been addressed.

None of this functionality was documented, as is was meant specifically
for domain specific implementation work arounds.

Signed-off-by: Timothy J Fontaine <tjfontaine@gmail.com>
node: ensure same AL inst only runs once

It was possible that the same AL instance was run twice if it were both
attached to the currentContext then again added to the new asyncQueue
generated for the new stack.

Signed-off-by: Timothy J Fontaine <tjfontaine@gmail.com>
node: compare AsyncListener instances, not uid's

Now that process.createAsyncListener() returns a unique object instance
it is no longer necessary to compare the uid's of the objects.

Signed-off-by: Timothy J Fontaine <tjfontaine@gmail.com>
test: give test-net-GH-5504 more time to run

On Windows debug builds, the test was failing because the timeout
was too short.
text: give more time to test-next-tick-error-spin

The previous timeout was too short for certain execution conditions
(Windows, debug build, first execution).
addons: build and test examples

fix #6910
node: `EmitExit` should not call `exit()`

Before this commit `RunAtExit` and `env->Dispose()` were never reached,
because `EmitExit` was always colling `exit`.
crypto: throw only in direct C++ methods

Do not throw in internal C++ methods, that clobbers logic and may lead
to the situations, where both exception was thrown and the value was
returned (via `args.GetReturnValue().Set()`). That doesn't play nicely
with v8.

fix #6912
crypto: add newline to cert and key if not present

After one of OpenSSL updates we have stopped accepting PEM private keys
and certificates that doesn't end with a newline (`\n`) character.
Handle this regression in `crypto.js` to make less trouble to our users.

fix #6892