it translate the arguments recieved from javascript, invokes the jni method
and return the exit code to javascript

expects to recieve a String[] array as an argument, invokes run_elf()
and communicates the return value by setting a static int of the invoking
class

other classes may need to read/write global javascript objects, the run
command which is going to be commited in the next patch deals with it

the test creates 2 threads, a client and a server,
server is echoing back message received from the client.

this test extends ScriptableObject, which means it can be accessible
in the scope of rhino.

cloudius.jar's main entry point embeds rhino and execute cli.js

instead of running rhino.jar -f <file>, we now embed rhino within our own class
and completely control the context of the script engine.

reuse Global() from org.mozilla.javascript.tools.shell to initialize
our Context, this is done so we'll have functions such as importPackage()
available to Javascript.

this patch still doesn't replace rhino shell.

Added build ("make") framework for compiling Java code we want to run in
OSv (in/with the Java payload), as well as JNI, i.e., OSv-specific C code
we want to run from the above Java code.

The Java source files in java/src/ are now all compiled during build
(see java/build.xml for the Ant file doing this compilation) and the
result is one JAR, build/$mode/java/cloudius.jar (/cloudius.jar in bootfs).
We can easily change build.xml to create more than one if we want.

As an example of JNI, I used the not-working-yet balloon feature.
java/src/com/cloudius/balloon/Balloon.java is the class
com.cloudius.balloon.Balloon which is supposed to have one "native"
(implemented in C) function giveup(). This function's implementation is
in java/jni/balloon.c. We get this file to compile to balloon.so (put
in /usr/lib/jni in the bootfs) by adding java/jni/balloon.so to the
"jni" list in build.mak.

If you don't know how write the ugly function signature as seen in
java/jni/balloon.c, you can run "javah com.cloudius.balloon.Balloon"
to build the empty functions needed for implementing the native functions
defined in the above class.

This allows running either testrunner.so, or one of the tests (e.g.
test/tst-fpu.so), as they now both export the same entry point.

Allows seeing UnsatisfiedLinkErrors while loading jars.

-jar terminates the JVM arguments, so that 'java -jar foo.jar -x' passes
-x to foo.jar, not the JVM.

A silly error causes a crash whenever arguments to the Java class are
supplied.

This will allow running unmodified tests with a main() entry point even
after splitting the test loader out of the kernel.