add meson build files

Closes #116.
Closes #171.
Closes #172.
Closes #175.

pkgconfig/meson.build

@@ -0,0 +1,22 @@
+pkgconfig_dir =	get_option('libdir') / 'pkgconfig'
+
+pkgconfig_conf_data = configuration_data()
+if root_prefix != '/'
+  pkgconfig_conf_data.set('PREFIX', root_prefix)
+else
+  pkgconfig_conf_data.set('PREFIX', '')
+endif
+pkgconfig_conf_data.set('LIB', get_option('libdir'))
+pkgconfig_conf_data.set('VERSION', meson.project_version())
+
+pkgconfig_files = [
+  'einfo.pc.in',
+  'openrc.pc.in',
+  ]
+
+foreach file : pkgconfig_files
+  configure_file(input : file,
+    output : '@BASENAME@',
+    configuration : pkgconfig_conf_data,
+    install_dir : pkgconfig_dir)
+endforeach