Add 'borderless' option

Until winit gives us more capabilities in regard to window decorations
this implements a simple switch that renders the window without any
title bar or border

src/config.rs

@@ -247,6 +247,10 @@ pub struct Config {
     #[serde(default)]
     background_opacity: Alpha,
 
+    /// Should draw window without borders
+    #[serde(default)]
+    borderless: bool,
+
     /// Keybindings
     #[serde(default="default_key_bindings")]
     key_bindings: Vec<KeyBinding>,
@@ -337,6 +341,7 @@ impl Default for Config {
             cursor_style: Default::default(),
             live_config_reload: true,
             padding: default_padding(),
+            borderless: false,
         }
     }
 }
@@ -1105,6 +1110,11 @@ impl Config {
         self.background_opacity
     }
 
+    #[inline]
+    pub fn borderless(&self) -> bool {
+        self.borderless
+    }
+
     pub fn key_bindings(&self) -> &[KeyBinding] {
         &self.key_bindings[..]
     }

src/display.rs

@@ -137,7 +137,7 @@ impl Display {
         let render_timer = config.render_timer();
 
         // Create the window where Alacritty will be displayed
-        let mut window = Window::new(&options.title)?;
+        let mut window = Window::new(&options.title, config.borderless())?;
 
         // get window properties for initializing the other subsystems
         let mut viewport_size = window.inner_size_pixels()

src/window.rs

@@ -183,14 +183,16 @@ impl Window {
     ///
     /// This creates a window and fully initializes a window.
     pub fn new(
-        title: &str
+        title: &str,
+        borderless: bool
     ) -> Result<Window> {
         let event_loop = EventsLoop::new();
 
         Window::platform_window_init();
         let window = WindowBuilder::new()
             .with_title(title)
-            .with_transparency(true);
+            .with_transparency(true)
+            .with_decorations(!borderless);
         let context = ContextBuilder::new()
             .with_vsync(true);
         let window = ::glutin::GlWindow::new(window, context, &event_loop)?;