Subversion log editing and other unfinished work

[Ryan Schmidt]

In preparation for moving MacPorts source code to git, we will be disabling
the ability to edit Subversion revision properties, including commit
messages (the svn:log property).

Once we move to git, editing commit messages won't be permitted anymore
either. While it's technically possible to do so, if you edit a git commit
message, the ID of that commit changes, as do the IDs of all commits based
on it, so changing the commit messages of published commits is not
recommended, and we don't want to allow it in our git repositories.

If there are any typos, missing ticket numbers or other minor changes you
had wanted to make in past commit messages, please do so by Monday, August
22, 2016, 12:00 Noon UTC.

After that time, please take an extra moment to proof read any commit
message before you save it, since you won't be able to change it later.

Now is also a good time to examine your MacPorts working copies for any
uncommitted work. If it's ready to be committed, or you can make it ready
quickly, please do so and commit it. If you wait until after we move to git,
you'll have to get a fresh copy of the code from GitHub and manually move
over your changes from the old Subversion working copy. The "svn diff --git"
command can help you do that.