Greatly simplified the UtilJ2eeCompat class by removing a series of variables and methods no more in use.
 The class was not thread safe and this didn't cause particular issues probably just because all the threads using it were passing ServletContext with the same server info value (because they were associated to the same servlet container); it was however inefficient.
 Now it is thread safe using the DCL pattern which I usually tend to avoid but is useful here.
 However this class should probably go away but before taking a decision I will start a discussion in the dev list.

git-svn-id: https://svn.apache.org/repos/asf/ofbiz/trunk@1622193 13f79535-47bb-0310-9956-ffa450edef68