Remove an uncessary svn_ra initialization from JavahL, and add a test
case for parallel RA session usage.

[in subversion/bindings/javahl]
* native/RemoteSession.cpp (RemoteSession::open): Do not call svn_ra_initialize.
* native/JNIUtil.cpp (JNIUtil::JNIGlobalInit):
   Catch and report errors from svn_fs_initialize and svn_ra_initialize.

* tests/org/apache/subversion/javahl/SVNRemoteTests.java
  (SVNRemoteTests.testParallelOpen): New test case.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1558389 13f79535-47bb-0310-9956-ffa450edef68