New version of the autoconf macros

[Stephane Bortzmeyer <bortzmeyer@pasteur.fr>]

Thanks to Devin Weaver <ktohg@tritarget.com>, who implemented everything which 
was missing, there is now a new set of autoconf macros for Java:

http://www.internatif.org/bortzmeyer/autoconf-Java/

* no longer need a Java compiler to test the Java VM or to test if a class is 
there,
* allows configure.in's author to test custom sources,
* and more.

Most Java programs are distributed as simple jars, without any easy mean to 
compile them, which I regard as an obligation for a Debian package (at least 
in main, see bug #49557 and the recent thread "On the use of pre-compiled 
classes in packages").

Therefore, I suggest Debian Java packagers to use tools like the above macros 
and mmake to allow an easy recompilation of Java programs.