Update readme.
Merge pull request #16 from dhui/readme

Update readme.
Link to our blog post.
Merge pull request #17 from dhui/readme

Link to our blog post.
Add tests for comparisons
Raise warnings when comparing to non-enum values

This should help when migrating to enums; the warnings don't stop
execution, but they will get logged as exceptions.
Merge pull request #18 from akshayjshah/warn

Raise warnings on comparisons to other types
Forgot to add to changelog and bump version
Merge pull request #19 from akshayjshah/warn

Forgot to add to changelog and bump version
Better warnings for cross-type comparisons

Set the stacklevel when warning so there's a better chance of warning
about the correct caller. Also log a complete stacktrace.
Use a named logger
Merge pull request #21 from akshayjshah/warn

Better warnings for cross-type comparisons
During enum construction, assert that all members are the same concrete type.

Having differing RichEnumValue subclasses used in the same RichEnum has proven
to be the source of many subtle bugs.
Merge pull request #22 from rbm/assert-same-types

Assert that all members of a RichEnum are the same concrete type
Membership tests without cross-type comparisons
Don't raise warnings on comparisons to None
Update changelog
Merge pull request #24 from akshayjshah/contains

Raise fewer warnings about cross-type comparisons
Suppress type comparison warning in RichEnum.lookup.

A reasonably common pattern is a RichEnumValue that has an attriibute that's
a list of some other RichEnumValue, usually related values. lookup() can then
be used to search said attribute for a specific member.

We always check up front to see if the object we're searching for and the
attribute value in question are exactly matching; in this case that generates
a type comparison warning that's spurious, since the next case (checking if
the attribute value is an iterable and seeing if the object we're searching
for is in it) does the correct thing.
Update CHANGELOG and package version