Summary

This PR updates the maint/maint-67 branch to 67.1.0.7.

Ah.. it turns out that I forgot that we were using merge commits in order to avoid the tedium of having to manually cherry-pick each single commit over to the maint branch. (For example, see PR #34).
However, I've already cherry-picked over some of the changes in to the maint branch, and while that does work, I could have just made a merge commit.

I've created this PR as a merge commit even though I already cherry-picked over changes in order to keep the history.
However, we can't go back and rewrite the commit history on a public repo, so this PR shows/appears as though it is making the same changes over again as was previously seen in other PRs.

But once this is merged then both branches should have the same original commits.

Note: Once this is merged, I plan on creating a new GitHub release, and then pushing out a new Nuget package.

PR Checklist

• I have verified that my change is specific to this fork and cannot be made upstream.
• I am making a maintenance related change.
• I am making a change that is related to usage internal to Microsoft.
• I am making a change that is related to the Windows OS build of ICU.
• CLA signed. If not, please see here to sign the CLA.