Allow users to re-initialize glog

http://code.google.com/p/google-glog/issues/detail?id=83
http://code.google.com/p/google-glog/issues/detail?id=125
http://code.google.com/p/google-glog/issues/detail?id=142



git-svn-id: https://google-glog.googlecode.com/svn/trunk@121 eb4d4688-79bd-11dd-afb4-1d65580434c0

src/utilities.cc

@@ -331,6 +331,7 @@ void InitGoogleLoggingUtilities(const char* argv0) {
 void ShutdownGoogleLoggingUtilities() {
   CHECK(IsGoogleLoggingInitialized())
       << "You called ShutdownGoogleLogging() without calling InitGoogleLogging() first!";
+  g_program_invocation_short_name = NULL;
 #ifdef HAVE_SYSLOG_H
   closelog();
 #endif