Implement Fullscreen Gallery option.

src/General/Config.coffee

@@ -165,7 +165,11 @@ Config =
       ]
       'Gallery': [
         true
-        'Adds a simple and cute image gallery.' 
+        'Adds a simple and cute image gallery.'
+      ]
+      'Fullscreen Gallery': [
+        true
+        'Open gallery in fullscreen mode.'
       ]
       'PDF in Gallery': [
         false

src/Images/Gallery.coffee

@@ -78,6 +78,9 @@ Gallery =
         candidate = post.file.thumb.parentNode
         if Header.getTopOf(candidate) + candidate.getBoundingClientRect().height >= 0
           image = candidate
+    if Conf['Fullscreen Gallery']
+      doc.mozRequestFullScreen?()
+      doc.webkitRequestFullScreen?(Element.ALLOW_KEYBOARD_INPUT)
     $.addClass doc, 'gallery-open'
     $.add d.body, dialog
 
@@ -261,6 +264,9 @@ Gallery =
       Gallery.nodes.current.pause?()
       $.rm Gallery.nodes.el
       $.rmClass doc, 'gallery-open'
+      if Conf['Fullscreen Gallery']
+        d.mozCancelFullScreen?()
+        d.webkitExitFullscreen?()
       delete Gallery.nodes
       delete Gallery.fullIDs
       doc.style.overflow = ''