common: create directory structure for rpmbuild

rpmbuild version 4.4.2.3 requires to create directory
structure before invoking when _topdir is defined.

Fixes: pmem/issues#3
Merge pull request #22 from plebioda/fix-make-rpm-on-sles11sp3

common: create directory structure for rpmbuild
blk: align ZERO and ERROR bit defs with spec

Thanks to alert reader @stellarhopper for this one!
common: fix _FORTIFY_SOURCE redefinition error

On Gentoo _FORTIFY_SOURCE=2 is defined by default so passing
-D_FORTIFY_SOURCE=2 causes error. Undefining _FORTIFY_SOURCE
and then defining fixes the problem.
Merge pull request #23 from plebioda/fix-fortify-source-on-gentoo

common: fix _FORTIFY_SOURCE redefinition error
nit: make .gitattributes safe for images
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'