* Patch the build system to allow building with an external zlib
instead of using the included one. Since the included zlib symbols
would be visible also to other JNI code (e.g. translators used by the
SWT libs), this could cause problems where a newer version was
required (e.g. libpng used by the PNG translator).
* Verified ALT_JDK_IMPORT_PATH as needed to be set.
Doesn't fully build yet. The build runs for a while, but eventually,
when building the jaxws/jaf sources, javac hangs. It blocks trying to
write to stderr, a pipe whose other end isn't read from (by Ant). I
haven't determined yet, whether the hang is an Ant bug and the issue
is javac simply encountering too many issues, or whether javac writing
a lot to stderr is just fine (verbose diagnostics?) and the hang is
actually a Haiku (pipe related?) bug, a combination of the two, or
something else entirely.