* [tests] Preserve all test fixtures.
This fixes the wildly diffetent number of tests when running xammac tests with and without linking.
Without linking:
> Tests run: 2446 Passed: 2321 Inconclusive: 9 Failed: 0 Ignored: 125
vs with linking:
> Tests run: 1885 Passed: 1802 Inconclusive: 4 Failed: 0 Ignored: 83
Now we run the same tests either with or without linking.
One test was updated to not fail when linking is enabled.
Also add a test to ensure all future test fixtures are preserved.
* Remove whitespace noise.
We've modified our NUnitLite to special-case the native types, so that they
can easily be compared with the standard types, but that doesn't work anymore
when switching to the official NUnit[Lite], so change all asserts to
explicitly convert whenever needed.