Swift 4, remove pod

Merge pull request Haneke#421 from lanserxt/master

Swift 4.0 support added

Don't fail if cancelled

Increase podspec version

Increase version

Merge pull request Haneke#172 from Haneke/swift-1.2

Update to Swift 1.2 and Xcode 6.3. Closes Haneke#151.

Remove debug line

Merge pull request Haneke#107 from Haneke/refactoring/set

Refactoring set

Merge pull request Haneke#102 from Haneke/feature/button_image

Feature/button image, closes Haneke#79 Haneke#81

Move convenience fetch functions from extensions into Cache.swift ins…

…tead. Fixes Haneke#98.