[fix] broken events before and after save on JModelAdmin. Related #4308

[phproberto]

This PR broke event B/C #4308

The default context passed to plugins on JModelAdmin save was:

$this->option . '.' . $this->name`

and it was replaced by:

$context = $this->option . '_' . $this->name;

That breaks all the existing plugins triggered before and after save events.

See:
https://github.com/joomla/joomla-cms/pull/4308/files#diff-39b4bc5cb02bbace2ee4febe8f54583eR1079

[phproberto]

Please do not merge because I want to create a getContext() function that:

• Will avoid this small errors in the future
• Will allow us to override the context

[amazeika]

@phproberto Thank you for noticing and reporting the issue with the typo that got introduced on our PR #4308. We've just submitted a PR for fixing this exact issue (see #5205). Thank you again.

[Bakual]

I'm closing this PR since I already merged the fix by @amazeika and said to not merge it yet anyway.

@phproberto Feel free to reopen if it's ready.

[phproberto]

Thanks @amazeika for the fast fix :) and thanks @Bakual for merging it. I'll prepare a new PR with the context changes which is much better because now the issue is already fixed.

[amazeika]

@phproberto No probs :). I really think that having the fix pushed first was very important. @Bakual did a great job on merging it almost instantly. The proposition you've made for the context getter is a good idea. This will certainly help on avoiding small errors with big consequences such as this.