I started from the 78ec8e commit then cherry-picked and squashed
commits that have been done in master since then, except the bad
commits that overwrote the tree (in master) with the tree in maint.
This commit also bumps the version number to 7.8.06.
The only "fix" that was made between 78ec8e and the previous commit
is e0072f which has been reported to break stuff.
This fixes a wrong merge that should not have happened:
commit 7e903a merges the master branch into the maint branch,
while we really want to keep the maint branch a bugfix-only
branch.
This commit reverts back the maint branch to its state before
merging the master branch. From there, we will fix remaining
problems with the maint branch (e.g. copyright issues) then
release this maint branch as Org-mode 7.8.05.