Fix «request», «sync» and «error» events documentation.

* signatures had wrong number of parameters;
* it was not documented that «error» is fired by fetch, sync and destroy methods.
Add support for runnig tests with jQuery-compatible libraries
Tweak fixture attachment.
Merge pull request #2875 from kmike/events-doc-fix

Fix «request», «sync» and «error» events documentation
Move favicon.ico to root directory so it shows up on all pages. Closes #2883