Fix unit test failure on Windows jdk7

If on Windows and using jdk7 unit test WikiImportingResponderAuthenticationTest
was failing due to test order dependency.

On Windows when using jdk6 order of execution of tests in WikiImportingResponderAuthenticationTest is:

    testUnauthorizedResponse
    testUnauthorizedResponseFromNonRoot
    testImportingFromSecurePageWithCredentials

On jdk7 the order is:

    testImportingFromSecurePageWithCredentials
    testUnauthorizedResponse
    testUnauthorizedResponseFromNonRoot

This change (documented by Oracle [here](http://www.oracle.com/technetwork/java/javase/compatibility-417013.html#jdk7)) caused both _Unauthorized_ tests to fail on jdk7 as the credentials are cached in WikiImporter from the first test and used in the subsequent tests thus causing the imports to be authorized and not then rendering the message **The wiki at .* requires authentication.** which both test check for.

A number of questions spring up about this.

1. Should I be using jdk6 or 7 for development?
2. Do any other developers use jdk7 on platforms other than Windows and not see this issue?
3. Do any other developers use jdk7 on Windows and not have this issue?