jPOS-102 use ScheduledThreadPoolExecutor
jPOS-102 use ScheduledThreadPoolExecutor

use ScheduledThreadPoolExecutor instead of Timer
This makes the code more readable, specially in the work-around
a race condition where a response could arrive exactly at expiration
time, code is much more readable now using future.cancel.

Removed unused variable and jmx-doc stuff we are not using anymore.

yinheli/jPOS,atancasis/jPOS,atancasis/jPOS,jpos/jPOS,jpos/jPOS,juanibdn/jPOS,alcarraz/jPOS,fayezasar/jPOS,barspi/jPOS,barspi/jPOS,alcarraz/jPOS,c0deh4xor/jPOS,juanibdn/jPOS,fayezasar/jPOS,poynt/jPOS,yinheli/jPOS,bharavi/jPOS,juanibdn/jPOS,atancasis/jPOS,poynt/jPOS,c0deh4xor/jPOS,c0deh4xor/jPOS,poynt/jPOS,sebastianpacheco/jPOS,bharavi/jPOS,jpos/jPOS,sebastianpacheco/jPOS,barspi/jPOS,alcarraz/jPOS,sebastianpacheco/jPOS,imam-san/jPOS-1,imam-san/jPOS-1,imam-san/jPOS-1,yinheli/jPOS,bharavi/jPOS