LU-13949 build: add autogen.sh into distribution tarball

LU-13949 build: add autogen.sh into distribution tarball

This patch adds autogen.sh and config/lustre-version.m4 into
Lustre distribution tarball so that customers can regenerate
aclocal.m4, config.h.in, autoMakefile.in and configure in
their build environments.

Change-Id: Ic6c5430b9a8b504ebc6a7618e141f1ea23b046a2
Signed-off-by: Jian Yu <yujian@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/40425
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Minh Diep <mdiep@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Shuichi Ihara <sihara@ddn.com>