Added RandomRangedNumberGenerator for item #146 with relevant unit tests.  Also added RandomRangedNumberCustomization and unit tests.   May need to add additional test cases to some of the unit tests especially for different numeric types.
Refactored RandomRangedNumberGenerator and added some comments.  Tried adding a test around ensuring RandomRangedNumberGenerator is thread-safe, but could not get such a test to fail first.
Refactored RandomRangedNumberGenerator around how the request limits are converted.  Removed some duplicate tests and refactored a few tests.
Added comments to RandomRangedNumberGeneratorTest to follow conventions in other tests for #146.
Ran BuildRelease.ps1, fixed all the errors, prior to sending pull request
Added link to good article about contributing.
Made RandomRangedNumberGenerator thread-safe with appropriate test.  Refactored some tests based on feedback.
Addressed review feedback.  Modified some tests, made correction for thread-safe dictionary access in RandomRangedNumberGenerator
Merge branch 'master' of https://github.com/dlongest/AutoFixture into dlongest-master
Incremented minor version,

in order to indicate that the addition of RandomRangedNumberGenerator and
RandomRangedNumberCustomization is a new feature, that resolves #146
(https://github.com/AutoFixture/AutoFixture/issues/146).