Stop using semigroup syntax in FingerTree

It results in unnecessary conversions/allocations
Stop using Option syntax in FingerTree

It results in unnecessary conversions/allocations
Stop using reducer syntax in FingerTree

It causes unnecessary conversions/allocations
Stop using Show and Order syntax in FingerTree

They result in unnecessary conversions/allocations
Clean up FingerTree formatting
Merge pull request #714 from ceedubs/fingertree-allocations

Remove unnecessary allocations in FingerTree