* ResourceWriterTest.cs: Added ctor tests. Added tests for AddResource

* ResourceWriterTest.cs: Added ctor tests. Added tests for AddResource
overloads. Added test for argument null checks. Added test for bug
#339074. Added test for invoking Generate () multiple times.
* ResourceWriter.cs: On 2.0 profile, use case-insensitive SortedList.
Changed exception messages and params to match MS. Allow null values
in AddResource overloads. In Dispose (bool), also generate resources
(header) if no resources were added. Fixes bug #339074. When Generate
is done, reset resources to null to prevent further editing.  This
also avoids the need for a separate bool to indicate whether generate
was already invoked. Code formatting.

svn path=/trunk/mcs/; revision=89412