Polishing:

- change some return types from int to bool;
  - add [ERROR] tag to log_error() output;
  - add [INFO] tag to log_info() output;
  - change log messages to be more consistent.


server-tools/instance-manager/IMService.cpp:
  Log polishing.
server-tools/instance-manager/commands.cc:
  Log polishing.
server-tools/instance-manager/commands.h:
  Eliminate warnings.
server-tools/instance-manager/instance.cc:
  Log polishing.
server-tools/instance-manager/instance_map.cc:
  Log polishing.
server-tools/instance-manager/instance_options.cc:
  1) Log polishing.
  2) Change int-return type to bool.
server-tools/instance-manager/instance_options.h:
  Change int-return type to bool.
server-tools/instance-manager/listener.cc:
  Log polishing.
server-tools/instance-manager/log.cc:
  Log polishing.
server-tools/instance-manager/log.h:
  Log polishing.
server-tools/instance-manager/manager.cc:
  Log polishing.
server-tools/instance-manager/mysql_connection.cc:
  Log polishing.
server-tools/instance-manager/mysql_connection.h:
  Change int-return type to bool.
server-tools/instance-manager/mysqlmanager.cc:
  Log polishing.
server-tools/instance-manager/priv.cc:
  Log polishing.
server-tools/instance-manager/thread_registry.cc:
  1. Print pthread_t as (unsigned long), not as (signed long)
  to avoid negative identifiers in output.
  2. Print thread id after it will be initialized, not before.
server-tools/instance-manager/user_map.cc:
  Log polishing.

server-tools/instance-manager/instance.cc

@@ -170,8 +170,8 @@ static bool start_process(Instance_options *instance_options,
     /* exec never returns */
     exit(1);
   case -1:
-    log_info("Instance '%s': can not start mysqld: fork() failed.",
-             (const char *) instance_options->instance_name.str);
+    log_error("Instance '%s': can not start mysqld: fork() failed.",
+              (const char *) instance_options->instance_name.str);
     return TRUE;
   }
 
@@ -699,10 +699,9 @@ void Instance::kill_mysqld(int signum)
   /* Kill suceeded */
   if (signum == SIGKILL)      /* really killed instance with SIGKILL */
   {
-    log_error("The instance '%s' is being stopped forcibly. Normally"
-              "it should not happen. Probably the instance has been"
-              "hanging. You should also check your IM setup",
+    log_error("Instance '%s': killed.",
               (const char *) options.instance_name.str);
+
     /* After sucessful hard kill the pidfile need to be removed */
     options.unlink_pidfile();
   }