Fix --test option to take a comma-separated list of test names just like nunit-console and test-harness
Modify --explore and --result options to use OutputSpecifications; drop --format option; fix up help message
Add tests of --include and --exclude options
Merge pull request #198 from nunit/issue-13

Issue 13 Completion.
Replace --appdomain option of test-harness with  --domiain:None/Single/Multiple
Reorganize namespaces for test-harness; remove -xml2 and -xml3 options and add -result; allow output specsifications for -explore and -result