Support dynamic Region creation on startup

Currently, GemFire gives the user the ability to add Regions dynamically at runtime using Dynamic Regions. Unlike declared, statically defined Regions in configuration (either via GemFire native cache.xml or GemFire's public API) Dynamic Regions are created on every member in the GemFire cluster and persisted across sessions/runs, or beyond the lifecycle of the cluster. This is because the Dynamic Region configuration meta-data is persisted to disk using a hidden meta-Region. Furthermore, Dynamic Regions are limited to being Sub-Regions and therefore require a top-level parent Region first. In addition, Sub-Regions are limited to being REPLICATE or PERSISTENT_REPLICATE.

However, due to design problems and other issues with GemFire's public API, it is not possible to create a Dynamic Region using GemFire's public API and thus Spring Data GemFire cannot fully support Dynamic Region functionality. See SGF-174 for further details.

This improvement request makes use of GemFire Function execution to create Regions dynamically, at runtime on-the-fly on any desired members in the GemFire cluster. Functions have the unique advantage in that they are not limited to creating Sub-Regions only, but in fact can be used to create any type of top-level Region. In addition, they can be targeted at specific members. The only disadvantage is that the dynamic Region creation cannot be persistent across runs.