Add helpers for common optparse-applicative backend command line.
Renamed ToDiagram to ToResult.
Added default implementations for anim and multi.
Fix warnings from -Wall.
Depend on safe for readMay.
Fix haddock error.
Add Parseable instances for colors.
Update Haddocks a bit.
Added loop options.
Simplify `mainArgs`, add `ToResult` instance for animations.
Update haddocks for CmdLine.  Simplify a few constraints.
Organization, fix a few spelling errors.
Merge branch 'master' of github.com:diagrams/diagrams-lib into optparse
Add link to tutorial.
Typo in link.
Fix spacing in haddock code blocks.
Adjusted command-line options to reflect old behavior.
Typo in haddocks.
Parameterize defaultAnimMainRender to take a lens for output.

We need to know how to modify the base case options to put a new file
name in place.  Another approach could have been classy lenses, but
this is simpler for now.
Merge pull request #135 from diagrams/optparse

Add helpers for common optparse-applicative backend command line.