Add Dropbox's zxcvbn library for realistic password strength estimation.

Upstream: https://github.com/lowe/zxcvbn. MIT License.
Modified for WordPress with a rot13 of the included word dictionaries, for PG-ness.

props duck_.
see #21737.

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Use Dropbox's zxcvbn library for our password meter.

The library was added in [25156].

props duck_.
see #21737.

Built from https://develop.svn.wordpress.org/trunk@25157


git-svn-id: http://core.svn.wordpress.org/trunk@25136 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Return to 'Item' for term updated messages for the link_category taxonomy.

props SergeyBiryukov, pavelevap.
fixes #18714.

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zxcvbn: Apply ROT13 when building the dynamic user_inputs dictionary.

The modified matcher assumes that the dictionaries are ROT13 encoded.
All of the static dictionaries were, but user_inputs wasn't. See #21737.

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git-svn-id: http://core.svn.wordpress.org/trunk@25138 1a063a9b-81f0-0310-95a4-ce76da25c4cd