fixed the conversion of the special '0000-00-00 00:00' date
bug #1311 fixed the conversion of the special '0000-00-00 00:00' date (fabpot)

This PR was merged into the 1.15-dev branch.

Discussion
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fixed the conversion of the special '0000-00-00 00:00' date

This PR reverts #1234 and add supports for PHP 5.5 is a simpler way. This also fixes #1241 and closes #1242.

Commits
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9b95570 fixed the conversion of the special '0000-00-00 00:00' date