Update package.json

Packages not updated:

jade (Breaking changes in 0.31.0, see visionmedia/jade#1094)
gm (Changes look harmless, but I'm not using this so couldn't test)
knox (Changes look harmless, but I'm not using this so couldn't test)
Rename array.js to array
Add support for image/file descriptions
Remove readIfExists

See http://nodejs.org/api/fs.html#fs_fs_exists_path_callback

Quote: "In particular, checking if a file exists before opening it is an anti-pattern that leaves you vulnerable to race conditions: another process may remove the file between the calls to fs.exists() and fs.open(). Just open the file and handle the error when it's not there."
Merge pull request #22 from DieBuche/fileDescriptions

Add support for image/file descriptions
Merge pull request #17 from DieBuche/patch-4

Update package.json
Merge pull request #23 from DieBuche/readIfExists

Remove readIfExists