Text alignment in SimpleMenu

Just a little nitty gritty. But it would be nice if this CSS style can be included in the next release.

ul#simplemenu li {
  text-align: left;
}

The issue here is that when the body is set to center alignment, all the menu items will be centered. As such usually I will need to include the code above to my theme's CSS file. I feel that it will be a good to add this in as default so SimpleMenu can be "theme agnostic".