Tag handler for <catch> in JSTL 1.0.
<catch> simply catches any Throwables that occur in its body and optionally exposes them.
super(); init();
if (var != null) pageContext.setAttribute(var, t, PageContext.PAGE_SCOPE); caught = true;
if (var != null && !caught) pageContext.removeAttribute(var, PageContext.PAGE_SCOPE);
caught = false; return EVAL_BODY_INCLUDE;
var = null;
super.release(); init();
this.var = var;