Bug in Timing tool example and before_handler docs improvement.

[Duiesel]

Hi guys!

I found an error in documentation related to TimingTool example.

before_handler never happens if there are an error at request body processing step.

So suggesting improvement of TimingTool example and before_handler event in docs.

[webknjaz]

@Duiesel are you suggesting that this causes an AttributeError? Could you post a little STR / demonstration?
Would you like to suggest a PR with a fix?

[Duiesel]

It causes nothing and this is the case.
If you get any error at request body processing step, any tool attached to hook point before_handler never called.
So it's not obvious and documentation says nothing about it.
I've looked at source code to figure out what happened.

Anyway will do a PR with a docs improvement.

[Duiesel]

@webknjaz If needed I could add simple example.

[webknjaz]

I think you can go ahead and just submit an improvement PR...