Second round of converting newstyle JavaHL native classes to cache all
method and field IDs.

[in subversion/bindings/javahl]
* native/jniwrapper/jni_object.hpp (ClassCache):
   Declare new cached classes: input_stream, output_stream and byte_buffer.
* native/jniwrapper/jni_class_cache.cpp (ClassCache::ClassCache):
   Init members and call static initializers for wrapped classes:
   InputStream, OutputStream and ByteChannel::ByteBuffer.

* native/jniwrapper/jni_channel.hpp,
  native/jniwrapper/jni_channel.cpp,
  native/jniwrapper/jni_io_stream.hpp,
  native/jniwrapper/jni_io_stream.cpp:
   Convert all wrapper classes to init static method IDs and use
   the cached class references.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1544489 13f79535-47bb-0310-9956-ffa450edef68
Add comments about ignoring errors.

* subversion/svnserve/svnserve.c
  (serve_socket): Document the error behaviour.
  (serve_thread, sub_main): Note where non-obviously ignoring an error.

git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1544490 13f79535-47bb-0310-9956-ffa450edef68