build: Add meson build system

Reuse the generated dbus interface .xml files from fprintd to avoid
unnecessary copies.

tests/meson.build

@@ -0,0 +1,46 @@
+tests = [
+    'fprintd',
+    'test_fprintd_utils',
+]
+
+foreach t: tests
+    test(t,
+        python3,
+        args: meson.current_source_dir() / t + '.py',
+        suite: ['daemon'],
+        depends: [
+            fprintd,
+            fprintd_utils,
+        ],
+        env: [
+            'G_DEBUG=fatal-criticals',
+            'FPRINT_BUILD_DIR=' + meson.build_root() / 'src',
+            'TOPSRCDIR=' + meson.source_root(),
+        ],
+    )
+endforeach
+
+add_test_setup('default_setup',
+    is_default: true,
+    env: [
+        'G_SLICE=always-malloc',
+        'MALLOC_CHECK_=2',
+        'MALLOC_PERTURB_=55',
+    ],
+)
+
+if find_program('valgrind', required: false).found()
+    glib_share = glib_dep.get_pkgconfig_variable('prefix') / 'share' / glib_dep.name()
+    glib_suppressions = glib_share + '/valgrind/glib.supp'
+    add_test_setup('valgrind',
+        env: [
+            'G_SLICE=always-malloc',
+            'VALGRIND=' + glib_suppressions,
+        ],
+        timeout_multiplier: 5
+    )
+endif
+
+if get_option('pam')
+    subdir('pam')
+endif