reslist API does not provide proper size regulation

[Christian BOITEL]

Following my discussion on this topic with rpluem on bugzilla, i am posting 
this one to submit you a change in the reslit pool management to ensure proper 
pool size regulation and some API changes to better handle this part of the 
list management.
 
See my initial toughts on 
http://issues.apache.org/bugzilla/show_bug.cgi?id=40348
 
Christian.