preserve transcript name during internal paste

for RT#388924

keep transcript name from original,
  rather than inventing TEMP-001
  but add uniqueness suffix _1 _2 etc. if necessary

(Session Window internal paste is deskpro-only
 and within one Otterlace instance)
New release tag humpub-release-79-06

Generated by /nfs/users/nfs_m/mca/gitwk-anacode/team_tools.stable/otterlace/release/scripts/otterlace_release_tag (otter/79-30-g116e810 from intcvs1:/repos/git/anacode/team_tools.git)