Test MacOS build for release-2018.1

Built on MacOS 10.12.6, from cspiegel/release-2018.1.

Test MacOS build with Hugo 3.3.0

All the below changes have been merged to master. Also Hugo 3.3.0 -- see PR.

Test MacOS build with smarter build script

Same as below, except I'm using Brad Town's build script, except that I did it right this time.

This should work on MacOS 10.7 through 10.12.

Test MacOS build with TADS 3.1.3, Unicode fix

Like the previous one, but also includes kerrymg's fix for non-ASCII pathnames.

This is my build script and should work on MacOS 10.7 through 10.12.

Test MacOS build with TADS 3.1.3

Three builds, created with two different tries at an updated build Mac process.

• gargoyle-20170328-t203-brew-mac.dmg is Brad Town's branch, built on MacOS 10.12. It should work on 10.8 and up, but I haven't tested that.
• gargoyle-20170401-town-t203-mac.dmg is Brad Town's branch, built on 10.7. Runs on 10.7 but not on 10.12.
• gargoyle-20170328-t203-mp-mac.dmg is my branch. Built on MacOS 10.7, runs on 10.7 through 10.12.

All versions include Chris Spiegel's work version of TADS 3.1.3.

Unofficial build for MacOS 10.12 "Sierra"

I created this build on a MacOS 10.7 machine, based on my "buildports7" branch. It should work on MacOS 10.7 through 10.12.

Thanks to @kerrymg for submitting the fix for the keyboard-input bug. (garglk#234)

Also includes @salty-horse's fix for image display problems (garglk@e3466aa).