Bug 12551 Move Trails fixes (aka "baby's first bug fix")

[Cattlesquat]

• Move trails no longer constantly re-initialized from what should only be starting parameters
• Move trails can be directly forced on/off/clear without need for indirection through "toggle", etc.

[Cattlesquat]

I thought I was deleting .classpath out of the commit here, not out of the project.

[Cattlesquat]

I think I've at least stopped it from wanting to delete .classpath from the project. No idea how to get it out of the PR which is what I wanted.

[yanlyub]

I think I've at least stopped it from wanting to delete .classpath from the project. No idea how to get it out of the PR which is what I wanted.

To get a file out of a PR it needs to be reset to the state it was in before the PR.

[Cattlesquat]

Okay yeah I'd have to figure out how to tell git to show me the history of an individual file (.classpath), and figure out what the reference in it is that I can then set to get that version. I could literally just delete the whole PR and re-make it in probably a 100th the time it would take to figure that out, unless you're ready to create that particular chapter of your Git how-to :-)

[yanlyub]

History of a single file, commit messages only: git log path/to/file.txt
History of a single file, full diff per commit: git log -p path/to/file.txt
Find commit hash for the commit you want to go back to, then:
Reset a single file to a certain commit: git checkout <commit hash> -- path/to/file.txt

[Cattlesquat]

Well, maybe that worked, maybe it didn't. It did something. Can't tell.

[Cattlesquat]

Oooh, "files changed" is 1 now -- I guess it DID work -- yay, thanks!

[yanlyub]

@uckelman - have a look at https://help.github.com/en/github/collaborating-with-issues-and-pull-requests/about-pull-request-merges#squash-and-merge-your-pull-request-commits , it seems to be possible to squash several commits of a PR so they appear as a single commit in master, this would be good for this PR in particular, otherwise the several changes to .classpath will still end up in master.

[Cattlesquat]

I made the new members private, and decluttered the comments. Should be more or less ready.