New button styles.

Using the new buttons:

* Button classes are now stackable.
* All buttons should use a base class of "button".
* Buttons default to the gray style (formerly "button-secondary"). Buttons can add a style by adding additional classes. To make a primary button, add the "button-primary" class.
* Buttons can be rendered in various sizes. In addition to the default size, you can add "button-large", "button-small", or "button-tiny".

For backwards compatibility reasons, "button-primary" and "button-secondary" both work as standalone classes.

get_submit_button() has been adjusted to handle shorthand button classes (i.e. button classes can be passed without the "button-" prefix).

props lessbloat, helenyhou, trepmal, nacin. see #21598.



git-svn-id: https://develop.svn.wordpress.org/trunk@21789 602fd350-edb4-49c9-b593-d223f7449a82

wp-admin/css/wp-admin-rtl.css

@@ -2303,7 +2303,6 @@ h3.tb {
 .button,
 .button-primary,
 .button-secondary,
-.button-highlighted,
 #postcustomstuff .submit input {
 	font-family: Tahoma, Arial, sans-serif;
 }
@@ -2473,7 +2472,6 @@ body.login.locale-he-il,
 .locale-he-il .button,
 .locale-he-il .button-primary,
 .locale-he-il .button-secondary,
-.locale-he-il .button-highlighted,
 .locale-he-il #postcustomstuff .submit input,
 .locale-he-il div.sidebar-name h3 {
 	font-family: Arial, sans-serif;