vmem: modify vmem benchmark, modify makefiles

The mt benchmark has been renamed to vmem_mt. The possibility of creating
pools in a directory has been added. Slight modifications to Makefiles.
Small vmem_valgrind test changes.
vmem: fix possible valgrind test match errors and valgrind version check
Merge pull request #20 from tomaszkapela/VMEM-benchmark-modification

vmem: modify vmem benchmark, modify makefiles
common: search for trailing whitespaces

Add searching for trailing whitespaces in README, Makefile*
and TEST* files to the top-level Makefile, because cstyle
looks for trailing whitespaces only in C source files.

[@andyrudoff tweaked this to fail the make if errors are found.]
Merge branch 'ldorau-common-search-for-trailing-whitespaces'