Update to mousetrap v1.4.5.

This fixes a bug present in Safari that would cause the 'v' hotkey to be
inserted into the address bar when opening an article.
Merge pull request #289 from alexmchale/mousetrap-v1.4.5

Update to mousetrap v1.4.5.
Merge branch 'master' of git://github.com/swanson/stringer into tweak