Fixed reserved bits to 1111 in af extension field

git-svn-id: http://svn.code.sf.net/p/gpac/code/trunk/gpac@5485 63c20433-aa62-49bd-875c-5a186b69a8fb
Fixed bug in max period CTS compute for live cases

git-svn-id: http://svn.code.sf.net/p/gpac/code/trunk/gpac@5486 63c20433-aa62-49bd-875c-5a186b69a8fb
Fixed gcc warning

git-svn-id: http://svn.code.sf.net/p/gpac/code/trunk/gpac@5487 63c20433-aa62-49bd-875c-5a186b69a8fb