Feature #4843 : blocking the download of file attachments attached to publications

- fixing bad display of history version list of a document (separation between the functional versions displayed and the technical versions registered in the JCR)
- upgrading the access control mechanism to take in account the context in which the access is verified
- adding a new request cache service to fix the thread cache service that doesn't work with ThreadLocale (JBoss problem)
- upgrading the version of FlexPaper API
- modifying simple document object structure (and the document converter) to handle more precisely document versions
- modifying the document exporting in order to not include document forbidden to download
- modifying the display of an attachment depending on whether it is forbidden to download it or not and depending on whether the user is allowed to download it or not
- adding menu item to attached file blocks
- adding the possibility of indicating roles to a document which are forbidden or not to perform a download on the attachment
- adding some unit tests in order to verify the management of the new forbidden download information stored into the Silverpeas JCR
- refactoring spring definitions in order to provide OrganizationController mock for all unit tests (lib-core project only)
- modifying the definition of the data structure of the Silverpeas JCR
- cleaning some code
- fixing a NullPointerException introduced by a new feature integrated in version of Silverpeas in which this feature is also integrated (5.14)