autogen.sh: fix autoreconf step

autogen.sh: fix autoreconf step

Running bootstrap and autoreconf from autogen.sh produced different
files in build-aux directory.  The reason is that gnulib usually have
newer version of these files and overwrites them after the autoreconf
step.

In order to fix it remove the --install and --force options, in addition
introduce --verbose option in order to reflect what bootstrap is doing.

Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>