* posix_users/preface.texi, shell/preface.texi: Add stock
acknowledgement paragraphs that are required when excerpting and
reusing text from POSIX standards per the agreement at
* common/opengroup_manpage_acknowledgement.texi,
common/opengroup_preface_acknowledgement.texi: New files.
* SUPPORT, LICENSE: New files.
* Numerous files touched as part of merging the 4.5 branch
onto the mainline development trunk and ensuring that the
script that cuts snapshots and releases works on the documentation.
