Add "-version" option to RunJava

Add "-version" option to RunJava, and therefore to java.so and the "java"
CLI command.

java -version now shows:

  java version "1.7.0_25"
  OpenJDK Runtime Environment (1.7.0_25-mockbuild_2013_07_27_13_36-b00)
  OpenJDK 64-Bit Server VM (build 23.7-b01, mixed mode)

I can't explain why the version on the second line is different than what
"java -version" on Fedora 18 shows for the same libjvm.so:

  java version "1.7.0_25"
  OpenJDK Runtime Environment (fedora-2.3.10.4.fc18-x86_64)
  OpenJDK 64-Bit Server VM (build 23.7-b01, mixed mode)

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>