Multiple installation issues when installing via civihydra on non-standard ports

1. I do local development with this environment that uses alternate ports.
2. The tool civihydra takes a CiviCRM archive (e.g. civicrm-5.4.1-wordpress.zip), creates a barebones CMS, and lets you go through the web-based installer. This installer differs from the headless/CLI routines used for day-to-day git-based dev.
3. When I run civihydra with the D7 and WP builds (e.g. civihydra create https://download.civicrm.org/civicrm-5.4.1-wordpress.zip), I get problems -- but they are different problems.

For the moment, I just want to file something so this doesn't get permanently forgotten. We can split into separate issues if appropriate.

Observations:

• For D7 sites, the civicrm.settings.php always has a malformed value of CIVICRM_UF_BASEURL.
  • This started sometime in 4.7.x but I haven't traced it.
• For WP sites, the civicrm.settings.php has a suitable value of CIVICRM_UF_BASEURL. However, the auto-detection of [civicrm.files] does not work correctly.
  • The problem is visible on every 5.x that I checked in (incl 5.0, 5.2, 5.5), so it started somewhere during 4.7.x. However, going back further -- to 4.7.20 -- the civihydra command does work.