Freeciv

The meson build file for Freeciv could likely be simplified and made easier to maintain by:

• Using dependency('foo' ...) instead of compiler.has_x
• Reducing boilerplate by using `foo_dep.found()` as a conditional
• Using meson feature option type instead of combo 'try', 'true', 'false'

Usability can be improved by providing a configure summary at the end of the script to provide useful troubleshooting information at the end of the process.
This is made easier by having `foo_dep` only be a dependency type rather than possibly being a list.