Corrected Eq and Arb instance names for the group in ActionLaws.
Merge pull request #340 from denisrosset/topic/actionlaws-typo

Corrected Eq and Arb instance names for the group in ActionLaws.
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
Replace some sys.errors with proper exceptions.
Merge pull request #345 from tixxit/fix/down-with-runtimeexception

Replace some sys.errors with proper exceptions.
Setting version to 0.9.0
Setting version to 0.9.1-SNAPSHOT
Update changelog, authors, guide, and readme for 0.9.0.

There is still a lot of work to be done making the documentation
more complete, up-to-date, and useful. But this commit is a start,
and adds the credits and changes for the newest relese.
Merge branch 'topic/partial-algebras'
Prototype implementation of Nullbox, thanks @non.