Messageboxes fixes and copy server's creds to clipboard.

Fixed all messageboxes that can use struct object as self name
(e.g. m for messageboxes in mainwindow). Should help to avoid some
errors.

Added possibility to copy server's credentials into clipboard
for ease of sharing.

context/context_object.go

@@ -69,7 +69,7 @@ func (ctx *Context) initializeCache() {
 }
 
 func (ctx *Context) InitializeClipboardWatcher() {
-    ctx.Clipboard = clipboardwatcher.New(ctx.Eventer)
+    ctx.Clipboard = clipboardwatcher.New(ctx.Cache, ctx.Eventer)
     ctx.Clipboard.Initialize()
 }