autotools -> meson

Original commit message:

> There are some known regressions regarding local testing setups - since
> everything was kinda half written with the expectation that build dir =
> source dir (which should not be true anymore). But everything builds and
> the test suite runs fine, after several hours spent debugging random
> crashes in libpqxx with MALLOC_PERTURB_...

I have not experienced regressions with local testing.

(cherry picked from commit 4b886d9c45cd2d7fe9b0a8dbc05c7318d46f615d)

src/meson.build

@@ -0,0 +1,86 @@
+# Native code
+subdir('libhydra')
+subdir('hydra-eval-jobs')
+subdir('hydra-evaluator')
+subdir('hydra-queue-runner')
+
+hydra_libexecdir = get_option('libexecdir') / 'hydra'
+
+# Data and interpreted
+foreach dir : ['lib', 'root']
+  install_subdir(dir,
+    install_dir: hydra_libexecdir,
+  )
+endforeach
+subdir('sql')
+subdir('ttf')
+
+# Static files for website
+
+hydra_libexecdir_static = hydra_libexecdir / 'root' / 'static'
+
+## Bootstrap
+
+bootstrap_name = 'bootstrap-4.3.1-dist'
+bootstrap = custom_target(
+  'extract-bootstrap',
+  input: 'root' / (bootstrap_name + '.zip'),
+  output: bootstrap_name,
+  command: ['unzip', '-u', '-d', '@OUTDIR@', '@INPUT@'],
+)
+custom_target(
+  'name-bootstrap',
+  input: bootstrap,
+  output: 'bootstrap',
+  command: ['cp', '-r', '@INPUT@' , '@OUTPUT@'],
+  install: true,
+  install_dir: hydra_libexecdir_static,
+)
+
+## Flot
+
+custom_target(
+  'extract-flot',
+  input: 'root' / 'flot-0.8.3.zip',
+  output: 'flot',
+  command: ['unzip', '-u', '-d', '@OUTDIR@', '@INPUT@'],
+  install: true,
+  install_dir: hydra_libexecdir_static / 'js',
+)
+
+## Fontawesome
+
+fontawesome_name = 'fontawesome-free-5.10.2-web'
+fontawesome = custom_target(
+  'extract-fontawesome',
+  input: 'root' / (fontawesome_name + '.zip'),
+  output: fontawesome_name,
+  command: ['unzip', '-u', '-d', '@OUTDIR@', '@INPUT@'],
+)
+custom_target(
+  'name-fontawesome-css',
+  input: fontawesome,
+  output: 'css',
+  command: ['cp', '-r', '@INPUT@/css', '@OUTPUT@'],
+  install: true,
+  install_dir: hydra_libexecdir_static / 'fontawesome',
+)
+custom_target(
+  'name-fontawesome-webfonts',
+  input: fontawesome,
+  output: 'webfonts',
+  command: ['cp', '-r', '@INPUT@/webfonts', '@OUTPUT@'],
+  install: true,
+  install_dir: hydra_libexecdir_static / 'fontawesome',
+)
+
+# Scripts
+
+install_subdir('script',
+  install_dir: get_option('bindir'),
+  exclude_files: [
+    'hydra-dev-server',
+  ],
+  install_mode: 'rwxr-xr-x',
+  strip_directory: true,
+)