Refactoring javagal bundles and jemma.osgi.ah.zigbee bundle

Javagal bundles  
 - Removed unused methods
 - Optimized imports
 - Added Error Manager class for managing errors
 - Added ThreadPoolManager class to manage better threads use in RestClientManagerAndListener.java   
   and  RestMessageListener.java
 - Code refactoring


jemma.osgi.ah.zigbee. bundle
 - Removed unused methods
 - Optimized imports
 - Code refactoring