V 0.15.2  2nd revision of Travel Time

Revision 2 of all	Travel Time in to 3 type
   - spot or instantaneous speed
   - Average spot speed :average of spot speed in specific windows
   - Space mean speed : speed calculate form difference in position and
time of 2 GPS points
V 0.15.3 Implement old source remover

1. Implement the additional thread to clear an inactive source.
V 0.15.3.2  Implement new Log system using log4j

1.Using log4j with two configuration file
(log4j.properties,log4j_println.properties)
Warn,Error, Fatla will be kept in logging.log
Otherwise will be printed on console
2. Keep all static variable in file bin/app.properties