Adds support of --debug command line parameters

It does not display everything yet.
It displays network events, webpage.sendEvent, webpage network listeners calls.

Refs #24
Bug fixed: webpage, after some redirections, callbacks were not called

When there is a redirection to a relative URL, the internal net logger
had the wrong URL to trace. We should resolve redirection URL.

Closes #68
More documentation on webpage API
Oups, revert some unwanted changes
Release of SlimerJS 0.8.2
Bumped version to 0.8.3pre
Merge branch 'v0.8'

Conflicts:
	API_COMPAT.md
	docs/conf.py
	docs/configuration.rst
	docs/release-notes.rst
	src/application.ini
	test/initial-tests.js
	test/test-environment.js