Renamed GroupAction to Action.

Because an Action can also exist for Semigroup and Monoid instances.
Merge pull request #338 from denisrosset/topic/rename-action

Renamed GroupAction to Action.
Fix bug with Rational(0D) constructor.

This would treat 0 (-0) as a value very close to, but not quite 0, and
we'd get back such a Rational (either positive or negative). This now
explicitly checks if the argument is 0 and returns Rational.zero.
Merge pull request #339 from tixxit/fix/rational-0D-bug

Fix bug with Rational(0D) constructor.
Corrected Eq and Arb instance names for the group in ActionLaws.
Split Action into LeftAction and RightAction.
Renamed the Action syntax classes accordingly instead of GroupOps, PointOps.
Added PartialAction implementation, with both Option-like and PartialFunction-like semantics.
Added implementation of Semigroupoid, PartialMonoid, Groupoid.
Added syntax for partial operations, with both Option-like and PartialFunction-like semantics.
Merge pull request #340 from denisrosset/topic/actionlaws-typo

Corrected Eq and Arb instance names for the group in ActionLaws.
Added "lifts" of (Left/Right/)PartialAction and Semigroupoid from A to the full algebra on Option[A].
Useful for tests.
Added partial algebra laws.
Added construction for forced Action from PartialAction.
Semigroupoid.isOpDefined has default implementation.
Remove combineOption from Semigroupoid.
Action extends PartialAction.
Fixes mixed case identifier bug when using case-insensitive file systems.
Corrected Semigroup override.
Clarify the project's use of the Typelevel CoC.
Merge pull request #342 from non/topic/coc-readme-updates

Clarify the project's use of the Typelevel CoC.
Fixed typo that lead to NumberFormatException

Fixed typo that lead to NumberFormatException when parsing intervals with
an open lower bound and an included upper bound.
Merge pull request #344 from rklaehn/issue343

Fixed typo that lead to NumberFormatException
add Rüdiger to AUTHORS