Revision 753428

THRIFT-300. A reimplementation of ax_java

Completely replace ax_java.m4 with ax_javac_and_java, which is
a clean-room implementation of an autoconf macro to detect Java.
It has some limitations compared to the ax_java macros in
The Autoconf Macro archive, but it has two key advantages.
It is not GPL-licensed.  It doesn't abort configure if Java is
not found.