TestingParty08: Clean up PageCreationTestCase

I'm looking for a simple example to add to the SimpleTest docs I'm writing, and chx suggested this one. However, it needs some work:

1. It's not name-spaced to the module.
2. It's not testModuleVerb, it's testModuleNounVerb
3. It doesn't ensure that page is created before it tries to add something.
4. $edit['title'] = rather than $edit['title'] =
5. Some assertions have descriptions, some don't.
6. Assertion descriptions should be wrapped in t() and aren't.
7. It shouldn't be assertNotNull() because node_load returns FALSE when it can't find anything. chx suggested assertNotIdentical($node, FALSE)