Generics for o.a.naming.*

Generics for o.a.naming.*
A little messy in places due to differences in env handling. Properties, Hashtable<?,?>, Hashtable<String,Object> and Hashtable<String,String) are all used and in a few places it is necessary to cast from one to the other.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@719153 13f79535-47bb-0310-9956-ffa450edef68