* proposed solution for Github Issue #33:
"TestCaseSource cannot refer to a parameterized test fixture"
 - allow specifying constructor parameters after data source method name
 - for the case where no method name would be required for the data
   source (ie, when the data source class itself implements
   IEnumerable), require the user to provide null for the method name
   - proposed to cater for the case where the only parameter to the
     constructor is a string
* Make the test around the random boolean generator a little sturdier
  after getting this test to fail whilst working on Issue #33
  - original code tried to get true/false variance in 10 attempts:
    the new test attempts up to 10000 times to get variance, quitting
    after the first time variance is found and bailing out with a useful
    message if variance isn't found in 10000 attempts.
* added missing XML document comment
* alter code style on changes to be more in line with how NUnit code currently is.
Merge pull request #56 from markwhitfeld/Issue33

Proposed solution for Issue #33