Add Incrementable and tests
Make it a bit weaker, rename to Successible
Make Successible stand independently of Monoid
Merge branch 'develop' of github.com:twitter/algebird into jco/incrementable
fix weird merge
Use Option
remove dud comment
Refactor per Oscar's infinite wisdom
refactor
Remove decayed
Fix DecayedValue
Merge pull request #238 from jcoveney/jco/fix_decayed

Fix DecayedValue
Add Typeclass methods
Merge remote-tracking branch 'upstream/develop' into jco/incrementable
All numerics in one go
Merge pull request #234 from jcoveney/jco/incrementable

Add Incrementable and tests