walker - Trim author email and support arrays

Looks like `author` field may contain an array. Took that in count by
converting the array to string. Also made sure possible emails get
trimmed out as long as they follow format `Foo Bar <foo@bar.com>`.
Merge pull request #36 from XhmikosR/master

md5checker/index.js: Fix JSHint warnings.
Update README.md files.
alertify: add author info.