Updates Spectacle 0.7.3-74e5543

Fixes issues found when on Mavericks. Released by eczarny on a Github:
https://github.com/eczarny/spectacle/issues/134#issuecomment-27186553
Merge pull request #1335 from leonelgalan/spectacle-update

Updates Spectacle 0.7.3-74e5543