Fix navigator properties to be read-only
Properly split up tests to make them work

The test.done() call was made too early and therefore the test didn't
check the second test run.
Add test for invalid script paths
Fix buggy script path test
Add Node.prototype.contains; fix Node.prototype.compareDocumentPosition; more.

- Add new level "living" to contain stuff from the WHATWG DOM Living Standard. It is now the default level. Fixes #767.
- Add document position constants to Node constructor.
- Implement Node.prototype.contains.
- Update Node.prototype.compareDocumentPosition to comply to the algorithm in the WHATWG DOM LS. Fixes #777.
- Add ENTITY_REFERENCE_NODE to obsolete node types.
- Fix DocumentType.prototype.parentNode to return the document node, not null. Fixes #778.
- Fix small issues with DOCTYPEs being unnecessarily uppercased, and processing instructions disallowed under HTML doc types (which is apparently an old W3C DOM Level 1 restriction, but is not in the WHATWG DOM LS).
No need to keep listing the tests in the README.
Version 0.11.0