add new default constructor for queue, using the number of (configured) disks to derive pool sizes
add new default constructor for queue, using the number of (configured) disks to derive pool sizes

git-svn-id: 4e7379b20b57f8e3dde5a0b7363f233184647162@3203 4e380d45-d1fd-0310-85a7-d18ec86df0ad

sriram-mahavadi/extlp,sriram-mahavadi/extlp,sriram-mahavadi/extlp,sriram-mahavadi/extlp