Merge pull request #46 from stoggi/macos-template-icon

Use templated icons for the menu bar in macOS

systray_darwin.m

@@ -159,6 +159,7 @@ void runInMainThread(SEL method, id object) {
 void setIcon(const char* iconBytes, int length) {
   NSData* buffer = [NSData dataWithBytes: iconBytes length:length];
   NSImage *image = [[NSImage alloc] initWithData:buffer];
+  image.template = YES;
   [image setSize:NSMakeSize(16, 16)];
   runInMainThread(@selector(setIcon:), (id)image);
 }