Spin Screenplay.Web and associated tests into its own solution

[craigfowler]

The project currently known as Screenplay.Web needs to be spun into its own solution, github project and also renamed. The new name shall be Screenplay.Selenium.

The rationale for this is:

• There could be multiple projects to support 'the web'. This one is quite specific to Selenium.
• The web project is likely to have multiple issues reported against it, as web browsers present a moving target. Having a separate solution and github project gives me a separate bug tracker.
• The version number for the Selenium project is also likely to lose sync with its parent.

[craigfowler]

As part of this, all issues need to be migrated.

[craigfowler]

Issues to migrate:

• 114

• 109

• 107

• 56

• 43

• 118

[craigfowler]

All issues migrated