Makefile: use one tab for install-cfg and added nop not to confuse some versions of shell

- apparently they evaluate wrongly the sequence: escape (\), new line,
  tab, done
lib/kcore: moved wrappers around sha256 to srutils

- the sha256 functions are in srutils and these created not necessary
  inter-library dependency, confusing some linkers
lib/srutils: new files with wrappers around sha256 and other hashing functions
pv: updated include paths to sha256 wrapper functions