[0.85] #4385: Fix purge action and NetworkPort checkboxes


git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@21491 35612d4c-9d10-0410-837c-bf9dd1be60d7
[0.85] #4385: Be more compliant by using inheritance


git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@21492 35612d4c-9d10-0410-837c-bf9dd1be60d7
[0.85] #4385: Document


git-svn-id: https://forge.indepnet.net/svn/glpi/branches/0.85-work@21493 35612d4c-9d10-0410-837c-bf9dd1be60d7