fix #47 - compare SortedSets properly to not through erroneous WatchError
ref #47, tweaks based on review
bump version
Expire can accept a timedelta value
Merge branch 'asherf-timedelta' into develop
Merge pull request #48 from noise/feature/issue47_watch_zset

fix #47 - compare SortedSets properly to not through erroneous WatchErro...
Merge branch 'release/2.9.0.7'