bug #4737 :  Now FileUtil.getMimeType() method uses first the Tika mime-type detector before using the file extension to detect the correct file mime-type
bug #4737 :  Use the Tika meta-type detection based upon both the file content and the file extension instead of only the one based upon the file extension

Conflicts:

	lib-core/src/main/java/com/silverpeas/util/MimeTypes.java
Bug #5021 - fixing sharing ticket expiration on the last day
Bug #5021 - fixing a security hole around file sharing
Bug #5021 - fixing the displaying of files attached at non valid publications