Add a shared Xcode scheme for the Spring framework target

[rastersize]

This PR adds a shared Xcode scheme for the Spring framework target. Such a file makes Spring work with Carthage (a dependency manager) as well as potentially continuous integration systems like Travis-CI*.

Further it removes a few Xcode project files which were committed to the repository before the git ignore file was added. Lastly the PR will also decrease the deployment target of the Spring framework target to iOS 8.0. It was set to 8.1 before while the SpringApp target was set to 8.0.

*) This would still require some more addition to the repository as well as configuring such system and the GitHub repository.

[jamztang]

Carthage build the branch correctly, but I'm seeing this error message.

dyld: Library not loaded: @rpath/libswiftCore.dylib
  Referenced from: /private/var/mobile/Containers/Bundle/Application/19B1CF62-41DC-4BBA-9969-38460E44BCB4/ObjectiveSpring.app/Frameworks/Spring.framework/Spring
  Reason: image not found

I followed suggested steps from stackoverflow but it doesn't solve my problem.

I'm not sure if there's more thing to do with the setup or it's the problem of Carthage.
My sample project is attached here

[clooth]

I didn't see any problems with this. I forked Spring, added the shared scheme and used that with Carthage and it worked just fine.

Edit: It might be due to my project being Swift from the beginning? Not sure.

Edit 2: It seems as if you need to tick the Xcode project to tell that there is Swift code included in the project before it works.

Is this only on your objective-c sample project?

[jamztang]

Possibly on an Objective-C project. We'll get a try and revert.

[jamztang]

Yes it's working on an Swift based project. There's still issues when I tried using Spring this way, we shall further discuss in #11