Add help, debug log, fix pid file creation

+ Add help in group chat
+ Add debug log ability
* A bit of cleanup
* Check against start uid rather than effective uid when creating pid-file

data/sample_config.json

@@ -11,5 +11,6 @@
         "cachetime": "data/cache/openweathermap.Id-Timestamp.db",
         "cachedata": "data/cache/openweathermap.Id-Data.db",
         "appid": "get_it_on_openweathermap.org"
-    }
+    },
+    "debug_log" : "/var/log/aleesa-telegram-bot/debug.log"
 }