segfaults cause i2p to not be able to restart

[sponge]

When a segfault happens, and the router does not exit cleanly and the wrapper detects this, but is not able to restart because router.ping exists. When the router exits unexpectedly like this, the wrapper should delete the router.ping file so that it can restart.

Example:

 #
 # A fatal error has been detected by the Java Runtime Environment:
 #
 #  SIGSEGV (0xb) at pc=0xb6fe118c, pid=31505, tid=2740644720
 #
 # JRE version: 6.0_30-b12
 # Java VM: Java HotSpot(TM) Server VM (20.5-b03 mixed mode linux-x86 )
 # Problematic frame:
 # V  [libjvm.so+0x62e18c]
   PSPromotionManager::copy_to_survivor_space(oopDesc*)+0x17c
 #
 # An error report file with more information is saved as:
 # /usr/local/i2p/hs_err_pid31505.log
 #
 # If you would like to submit a bug report, please visit:
 #   http://java.sun.com/webapps/bugreport/crash.jsp
 #
 JVM exited unexpectedly.
 Launching a JVM...
 Wrapper (Version 3.1.1) http://wrapper.tanukisoftware.org

 Starting I2P 0.8.13-25
 ERROR: There appears to be another router already running!
        Please make sure to shut down old instances before starting up
        a new one.  If you are positive that no other instance is running,
        please delete the file /usr/local/i2p/router.ping
 <-- Wrapper Stopped

This happens on occasion here. Not sure exactly what the problem is, but I am suspecting a bad RAM module…

[killyourtv]

Duplicate of #633