use REGRESS_HOST to specify the host to listen to; use in CI some CI envs don't like `listen on localhost' but tolerate INADDR_ANY or IN6ADDR_ANY_INIT.

rework the configure script now it resembles less oconfigure and more the configure scripts I'm using in my recent projects. I'd argue it's more easy to use it.

remove regress/sha we can use cmp to tell if two files are different, which also has the benefit of being available everywhere and reporting the byte offset of the first difference. Reduces the test dependencies on some systems.

ignore and clean fcgi.sock

rework `make dist'

refactor the makefile / configure steal more (good) stuff from mandoc-portable :)

check for the expected page in test_auto_index not just the number of lines, check the full page!

add tests for the type block

typo

retire the old gg

rename `runtime' to `regress' while there also kill an unused rule `regress', it's now redundant since all the tests are run together.

run all kinds of tests via tests.sh/runtime while there also change the dependency in the makefile: iri_test should be alone, not as deps of `data'.

allow to run only a subset of the runtime tests with make TESTS='test_1 test_2 ...' regress now it's possible to run only that specified subset of tests. It's really useful during debugging :)

rework the regression suite The tests are still there, the suite is equivalent to the old one, but this one is better structured. The biggest annoyance I had with the old one was that it wasn't straightforward to test only a specific set of tests. It's still impossible, but it's way easier to do it now. This extract all the tests to their own functions. It's overall better in all possible regards.

update clean target