THRIFT-208. Fix ax_java.m4 for Ubuntu 8.10

THRIFT-208. Fix ax_java.m4 for Ubuntu 8.10

On Ubuntu 8.10, /bin/sh is a symlink to dash (a minimal
Bourne-compatible shell).  ./configure is smart enough
to detect when the shell it is run with is missing features.
In such cases, it switches to a more capable shell (like bash).
This causes it to enable certain shell constructs that are
not supported by dash.  However, the Autoconf macro file that
we use to detect Java support interacts poorly with Autoconf
because it uses divert(-1) for large comments.  This somehow
causes configure to set SHELL to /bin/sh.  As a result, the
libtool script generated during the build process is not
compatible with the shell that is used to run it (if a recent
version of libtool is in use).

This change replaces all of the "divert(-1)" comments
with more traditional "dnl" comments.  This allows Thrift
to build on Ubuntu 8.10.

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@728756 13f79535-47bb-0310-9956-ffa450edef68