Return hash null when a file don't exist.

getMTime() Return -1 when a file don't exist.
Optimize the hash computation.
[auto] Merge from Iterator

    • #f144983 — Return hash null when a file don't exist. (Metalaka, 2014-02-13)
    • #896e89c — Optimize the hash computation. (Ivan Enderlin, 2014-02-18)

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Merge branch 'master' of /var/lib/git/repositories/Library/Iterator