Update phpDoc to make it standard compliant

PHP Doc stipulates that for `@var` comments, the type should come first (see http://en.wikipedia.org/wiki/PHPDoc#Tags)
merged branch fzaninotto/patch-1 (PR #571)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #571).

Discussion
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Update phpDoc to make it standard compliant

PHP Doc stipulates that for `@var` comments, the type should come first (see http://en.wikipedia.org/wiki/PHPDoc#Tags)

Commits
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5895afb Update phpDoc to make it standard compliant