Clean up the remaining warnings in JavaHL tests.

[in subversion/bindings/javahl]
* tests/org/apache/subversion/javahl/SVNTests.java
  (SVNTests.getStatusArray): Remove useless cast.
* tests/org/apache/subversion/javahl/BasicTests.java
  (BasicTests.testMergeReintegrate): Suppress deprecation warnings from this
   test case, since it exercises a deprecated method.
  (BasicTests.acquireMergeinfoAndAssertEquals,
   BasicTests.assertExpectedDiffSummaries): Remove useless casts.

* tests/org/apache/subversion/javahl/WC.java:
   Do not import (deprecated) class junit.framework.Assert.
  (WC): Inherit from TestCase instead, and update all
   assertions to use the inherited methods.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1544594 13f79535-47bb-0310-9956-ffa450edef68