• Bring what's shown in the version string in line with my other projects (URL, description, git hash and date for release-mode non-final builds only, potential for colours in the future)
• Show +git or -git depending on feature status
• Tests for the above, and for checking that the command-line flag is warned about
I read through every file and applied a couple of rustfmt suggestions. The brace placement and alignment of items on similar lines has been made consistent, even if neither are rustfmt's default style (a file has been put in place to enforce this). Other changes are:
• Alphabetical imports and modules
• Comma placement at the end of match blocks
• Use newlines and indentation judiciously
• Spaces around associated types
• Spaces after negations (it makes it more clear imho)
• Comment formatting
• Use early-returns and Optional `?` where appropriate
