use mutable.ArrayBuffer instead of Vector in count est sketch
Merge branch 'mutable' into mutable-2.9.2
use mutable bitset in bloomfilter
Merge branch 'mutable' into mutable-2.9.2
Merge branch 'scala-2.9.2' into mutable-2.9.2
Merge branch 'scala-2.9.2' into mutable-2.9.2