Fix Xcode 8.3 warnings

Merge pull request ZipArchive#328 from MaddTheSane/fileSysRep

Use -fileSystemRepresentation for file names

Fix broken test in SSZipArchiveTests.m

pod version bump

Bump Podspec

Update swift test project for swift 3 and xcode 8

fix main source build

podspec bump

bump podspec and fix swift example and add autolayout constraints.

Bump podspec to 1.2