Fixed a path in buildpackage.sh
Fixed tests about version number
Main tests: add a parameter --only-web-servers

It allows us to launch only web servers to test them
in a classical browser.
Fixed an issue with redirection to a 'directory'

Server web often add a slash to the response url when it
corresponds to a directory.

Closes #90
update release notes for 0.8.4
Docs: add a notice about window.content. Refs #100
Docs: update some links to developer.mozilla.org
Better algorithm to compare images during tests on webpage.render()

The rendering engine of Gecko can add some blur on edge of square
in zoomed image. So we cannot compare the equality of color of
each pixel. We should compare if colors are almost equal.
Fixes redirection: better url comparison

we had an issue when a redirection was made to http://foo.com:80/
which is then stringified as http://foo.com: the comparison was false.

Closes #90
fixes webpage.plainText: should return only text content

It should not return content of invisible elements, script and style
elements, as PhantomJS does.
A flag plainTextAllContent in settings allow to have the previous
behavior.

Closes #97
Documentation about webserver
The webserver supports now asynchronous responses

Closes #91
Release of SlimerJS 0.8.4
Merge branch 'v0.8'

Conflicts:
	buildpackage.sh
	docs/conf.py
	docs/release-notes.rst
	src/application.ini
	test/initial-tests.js
	test/main-tests.js
	test/test-environment.js