Improving code coverage of tests for opt and orderby
Improved code coverage

1. intersect_range (also fixed minor bug)
2. concat_range
3. lookup_range (removed dead-code)
Updated TODO
Merge branch 'mrange__improve_codecoverage'
Fixes related to opt tests
Merge branch 'mrange__opt_test_fixes'
Merge ..\..\CodePlex\cpplinq