Replace typedef enums with typedef NS_ENUM.
For one thing, it make Swift happier. Also, we don’t have to worry about what size/type the value is.
Change ints in NS_ENUMs to NSIntegers.
Change SUCharacterType to an NSInteger.
Merge pull request #398 from MaddTheSane/nsEnumedEnums

Change enums to NS_ENUMs
Warn when version is missing
Code formatting
Retain binary compatibility with older versions of Sparkle.
Use standard Denial-of-Service acronym.
Update podspec for v1.8.
Add CodeSignOnCopy, RemoveHeadersOnCopy attributes.
Silence warnings in XCTest framework.
Use proper variables in shell scripts.
Keep settings in xcconfig, remove unnecessary ones.
Properly set install names and rpaths for targets.
Copy Autoupdate.app in a separate phase.
Reduce duplication and macros.
Use Info.plist keys instead of macros.

This helps ensure that all code paths are compiled during development, reducing the chance of build errors (especially in CI). Additionally, developers can change these values without having to rebuild Sparkle (but it is still safe because modifying the plist will break the code-signing seal).
Further reduce macro usage.
Silence direct ivar access warning.
Simplify code path.