Add utilities for file content translation to JavaHL.

* build.conf (private-built-includes):
   Added org_apache_subversion_javahl_util_SubstLib.h.

[in subversion/bindings/javahl]
* src/org/apache/subversion/javahl/SVNUtil.java
  (SVNUtil.substLib,
   SVNUtil.EOL_LF SVNUtil.EOL_CR SVNUtil.EOL_CRLF,
   SVNUtil.buildKeywords, SVNUtil.translateStream): New.
* src/org/apache/subversion/javahl/util/SubstLib.java: New class.

* native/jniwrapper/jni_string_map.hpp,
  native/jniwrapper/jni_string_map.cpp: New; JNI wrapper for
   the java.util.Map class with String keys.
* org_apache_subversion_javahl_util_SubstLib.cpp: New;
   Implementation of native methods in class SubstLib.

* tests/org/apache/subversion/javahl/UtilTests.java
   (UtilTests.testBuildKeywords): New testcase.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1542401 13f79535-47bb-0310-9956-ffa450edef68