Fixed bug on windows: module loading can fail

Because of the use of anti-slashes into path, the module loading can fail in some case, when
for example when we indicate a path to require.

closes #61
Fixed issue with phantom.libraryPath and webpage.libraryPath

on windows with path containing slashes.
More documentation on webpage
Add a CONTRIBUTING file
Updated CONTRIBUTING and web site
Merge branch 'v0.8'

Conflicts:
	docs/release-notes.rst
	test/initial-tests.js
	test/test-environment.js