Quartic formula, no obvious bugs
Various nits and cleanups
Export cubForm' and quartForm'
Add underscores to silence warnings, and add warnings to match with Travis CI
Merge pull request #187 from diagrams/quartic

Add function to find roots of quartic polynomials
Update Arrowtest for Measure, tailLength change

I've arbitrarily chosen measures and line weights.
They can likely be improved.
update arrowtest
reduce imports in Image.hs
update Changes for 1.2
CHANGES updates
travis: use GHC 7.8.2
travis: use most recent cabal
bump to 1.2
allow semigroups 0.15 and optparse-0.9
CHANGES: typos, capitalization

Capitalize some type names, to make it more obvious that they are types
some diagrams-haddock fixes
finish diagrams-haddock fixes
check in newly generated diagrams-haddock images
Allow lens-4.2
transform Local Measure in arrow styles

closes #193