Replace actual test (exif) by a new dynamic system of check integrity.
Anomalies are listed with automatic correction if it's possible.
Merge BSF 2064:2066 into branch-1_7
git-svn-id: http://piwigo.org/svn/branches/branch-1_7@2067 68402e56-0260-453c-a942-63ccdbb3a9ee