This is the first step to move keyfile to libnm. For now, only
copy the files to make later changes nicer in git-history.

  /bin/cp src/settings/plugins/keyfile/reader.c libnm-core/nm-keyfile-reader.c
  /bin/cp src/settings/plugins/keyfile/reader.h libnm-core/nm-keyfile-reader.h
  /bin/cp src/settings/plugins/keyfile/utils.c  libnm-core/nm-keyfile-utils.c
  /bin/cp src/settings/plugins/keyfile/utils.h  libnm-core/nm-keyfile-utils.h
  /bin/cp src/settings/plugins/keyfile/writer.c libnm-core/nm-keyfile-writer.c
  /bin/cp src/settings/plugins/keyfile/writer.h libnm-core/nm-keyfile-writer.h