Add Workspace and Frameworks project (Carthage Support)

[Jeehut]

I'm not sure why #624 was not merged back then, but since quite some time has passed since then I expect that PR not to work any more. So I made a clean fork with the most current iCarousel to get Carthage support and fix an issue (#782).

I've tried not to change anything except what was really needed, specifically here's what I did:

• Create a new project with iOS & macOS framework targets with shared schemes
• Create a workspace with my new project and all test & example projects included
• Stopped sharing any other schemes except for the framework schemes (to fix Carthage Installation fails for usage via Checkouts #782)

Using my fork via Carthage (until this is merged) is as easy as including this to your Cartfile:

github "Dschee/iCarousel" "master"

Note that this PR also solves #667.

[Jeehut]

Note that this alone didn't solve the issue. See here where I also have a working solution.