[Bug 4710] - Saving selected manifest

Previously the selected manifest wasn't being updated on disk so it
wasn't loading the users selections.
[Bug 4711] - Adding support for specifying domain
[Bug 4711] - Setting test URLs correctly

Tests were previously created before the domain override was checked and
the tests contained the full URL to the test page; this is probably not
ideal, but to limit the scope of the refactor I'm just using the right
domain now.
Merge branch 'master' of https://github.com/tdupont750/Selenite