Provide a "terse paths" mode

[jd0-sag]

Running tests on Windows sometimes runs into the 260 char path length limit on that platform.

We can reduce how much galvan aggravates this issue by creating a mode where it will always opt to create short path names. While this mode could be set via some kind of variable, we would probably want Windows to default to enabled while other platforms could continue with the more descriptive paths.