vmem: extend test vmem_stats to check multiple pools
vmem: fix vmem_freespace, vmem_valgrind unit tests

-Fix sporadical assert failures in vmem_freespace
-Change message about skipped tests in UT vmem_valgrind
Merge pull request #29 from spawlows/vmem-fix-unstable-tests

vmem: fix vmem_freespace, vmem_valgrind unit tests
Merge pull request #30 from spawlows/vmem-stats-test-multiple-pools

vmem: extend test vmem_stats to check multiple pools