Add new example

This patch adds new example showing the use of a two level SASCompoundHeap_t
name struct using SPHSetupProjectContext, getProjectContextByName and
SPHContextAddName.This shows how to set up a persistent name space
with separate projects (each project has it own SPHContext_t).

	* examples/Makefile.am: Add example_sph_4.
	* examples/Makefile.in: Regenerate.
	* examples/example_sph_4.c: New file.