Release v0.7.3

[casey]

• Bump version: 0.7.2 → 0.7.3
• Update changelog
• Update man page
• Update config test

[casey]

@huzhenghui Hi! I really liked your idea of using a recipe chooser to choose a recipe to run, so I added it directly to just.

I did it in #680, which is included in this release. For info about how it works, I added a readme section describing the feature.

You can use it with choose-gui by setting JUST_CHOOSER to /usr/local/opt/choose-gui/bin/choose, like so:

JUST_CHOOSER=/usr/local/opt/choose-gui/bin/choose just --choose

Or by passing the chooser as an argument:

just --choose --chooser /usr/local/opt/choose-gui/bin/choose