Solution for JIRA issue SGF-248 - bootstrapping a Spring ApplicationContext/container from within GemFire (DO NOT MERGE... YET).

The purpose of this PR is for review by the Spring XD team and their efforts to integrate GemFire into the Spring XD runtime seamlessly.  The changes introduced by this PR makes it possible to start a Spring container and ApplicationContext in a running GemFire Server JVM process and also enable Gfsh to start a Server with cache.xml bootstrapping a Spring ApplicationContext loading SDG XML namespace configuration meta-data to mostly configure the GemFire instance.