Changes to be committed:
	modified:   src/main/java/wula/Sample.java
	new file:   src/main/java/wula/thread/EmptyPoolException.java
	new file:   src/main/java/wula/thread/PoolManager.java
	new file:   src/main/java/wula/thread/ThreadPool.java

Add Thread Pool feature
 Changes to be committed:
	modified:   src/main/java/wula/http/HTTP.java

[HTTP] update
 Changes to be committed:
	new file:   web/webapps/context/WEB-INF/cache-config.xml

[Cache] add cache config