Implement Gtk Network Status (#165)

Implemented
- Switch reacts to burrow socket and network changes 
- meson as build system
- Basic diagnostics to ensure burrow is installed properly
- Flatpak / Meson Building

burrow-gtk/src/meson.build

@@ -0,0 +1,34 @@
+# config.rs.in
+global_conf = configuration_data()
+global_conf.set_quoted('ID', app_id)
+global_conf.set_quoted('VERSION', meson.project_version())
+global_conf.set_quoted('LOCALEDIR', localedir)
+global_conf.set_quoted('GETTEXT_PACKAGE', app_name)
+config = configure_file(
+    input: 'config.rs.in',
+    output: 'config.rs',
+    configuration: global_conf,
+)
+
+run_command(
+    'cp',
+    meson.project_build_root() / 'src' / 'config.rs',
+    meson.project_source_root() / 'src',
+    check: true,
+)
+
+# Cargo Build
+cargo_build = custom_target(
+    'cargo-build',
+    build_by_default: true,
+    build_always_stale: true,
+    output: meson.project_name(),
+    console: true,
+    install: true,
+    install_dir: get_option('bindir'),
+    command: [
+        'env', cargo_env,
+        cargo_bin, 'build',
+        cargo_opt, '&&', 'cp', 'target' / rust_target / meson.project_name(), '@OUTPUT@',
+    ]
+  )