Build and run examples as tests

This PR turns examples into tests:

• Autotools: option --enable-examples is removed, the examples are built and run with make check;
• CMake: option MTIME_BUILD_EXAMPLES is removed, the examples are built with make and run with make test when -DBUILD_TESTING=ON.

Depends on !76 (merged).

added 3 commits

• 771d4de3 - Fix the uniq example
• 5fa696c0 - autotools: run examples as tests
• 53f34aca - cmake: run examples as tests

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changed the description

added 3 commits

• 6aead8f3 - Fix the uniq example
• a6ea1619 - autotools: run examples as tests
• 253ff439 - cmake: run examples as tests

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marked this merge request as draft

changed the description

marked this merge request as ready

enabled an automatic merge when all merge checks for 253ff439 pass

merged