* DirectoryTest.cs: Restore original CurrentCulture on teardown.

* DirectoryTest.cs: Restore original CurrentCulture on teardown.
* FileSystemInfoTest.cs: Restore original CurrentCulture on teardown.
Removed stray tabs. Code formatting.
* FileTest.cs: Restore original CurrentCulture on teardown. Removed
stray tabs. Changes spaces to tabs.
* ThreadTest.cs: Added tests for bug #81930.
* CultureInfoTest.cs: Added exception tests when invoking NumberFormat
or DateTimeFormat on a neutral culture. Added tests for bug #81930.
No longer derive from deprecated Assertion class. Added tests for
GetCultureInfo (2.0).
* ArrayTest.cs: Added test for bug #81941.
* ByteTest.cs: Restore original CurrentCulture in teardown.
* DecimalFormatterTest.cs: Restore original CurrentCulture in teardown.
Code formatting.
* DecimalTest.cs: Code formatting.
* DoubleFormatterTest.cs: Test relies on specific culture, so set it
up here. This worked before since the CurrentCulture was set in another
TestFixture, and the original one was not restored.
* FloatingPointFormatterTest.cs: Same.
* NumberFormatterTest.cs: Same. Removed stray tabs and fixes code
formatting.
* SingleFormatterTest.cs: Restore original culture on teardown. Code
formatting.
* SingleTest.cs: Same.
* StringComparerTest.cs: Restore original culture on teardown.

svn path=/trunk/mcs/; revision=80626