Libadwaita gui (#19)

Major Update: Functional GUI Frontend!

src/config.rs

@@ -64,6 +64,7 @@ fn find_arg(key: &'static str) -> Result<Option<String>, MissingParameter> {
     Ok(None)
 }
 
+#[derive(PartialEq, Eq)]
 pub enum Frontend {
     Gtk,
     Cli,
@@ -96,6 +97,9 @@ impl Config {
         };
 
         let frontend = match frontend {
+            #[cfg(all(unix, feature = "gtk"))]
+            None => Frontend::Gtk,
+            #[cfg(any(not(feature = "gtk"), not(unix)))]
             None => Frontend::Cli,
             Some(s) => match s.as_str() {
                 "cli" => Frontend::Cli,