I've done the same thing that "WeaverSnap" said in answer to this question.
My accordion is just like the JSFiddle he posted.
The problem is, the chevron icons start in the wrong state, but fix themselfs after one of the panels get toggled.
It's a minor issue but i think it can be fixed.
Here is the CSS he provided: (I changed "FontAwesome" to "Glyphicons Halflings" BTW)
/* CSS Method for adding Font Awesome Chevron Icons */
.accordion-toggle:after {
/* symbol for "opening" panels */
font-family:'FontAwesome';
content:"\f077";
float: right;
color: inherit;
}
.panel-heading.collapsed .accordion-toggle:after {
/* symbol for "collapsed" panels */
content:"\f078";
}