** Added security check into ForgePdfServlet
** Added new permissions MATERIAL_ACCESS, MATERIAL_MODIFY and
MATERIAL_DELETE
** Added role MATERIAL_USER (has all permissions mentioned above)
** Attached USER and ADMINISTRATOR users into MATERIAL_USER
** Added permission checks for MATERIAL_ACCESS, MATERIAL_MODIFY and
MATERIAL_DELETE
** Added null / empty check into JsonMapConverter
** Added permission checks into ForgeMaterialActionsBackingBean