The constructor ZInputStream(boolean nowrap) had ingored its argument.
issue7: contention on static synchronized gen_codes() under high load

   https://github.com/ymnk/jzlib/issues/7
new Inflater() should not throw an exception.
inflater should be able to detect the format of deflated data.

  * an enum type JZlib.WrapperType is added.
      JZlib.W_NONE
      JZlib.W_ZLIB
      JZlib.W_GZIP
      JZlib.W_ANY

  * Inflater with JZlib.W_ANY can inflate any deflated data
    even if it has zlib header or gzip header or no-header.

  * Deflate can easily generate zlib-ed data, gzip-ed data or nowrap data
    with a WrapperyType parameter.

  * following methods are added,
    ZStream#inflateInit(JZlib.WrapperType)
    ZStream#inflateInit(int, JZlib.WrapperType)
    ZStream#deflateInit(int, int, int, JZlib.WrapperType)

  * refer following test for how-to specify Wrappertype,
    src/test/scala/WrapperTypeTest.scala
JZlib.WrapperType should be public.
JZlib.WrapperType is renamed to JZlib.HeaderType.
In case W_ANY for nowrap mode, avail_in and total_in should be also updated.
Deflater and Inflater support JZlib.HeaderType.
new Inflater(W_GZIP) should fail for the deflated data with zlib-header.
refactoring.
HeaderType is renamed as WraperType.

The date will have a header and a trailer, so WrapperType must be better.
Merge branch 'incorporate_netty_fixes'