At least now the back button won't trigger the drop-down notification.

It was formerly on <LI> but now it's on <A> as we now allow bare <A>s to
have context menus.

1. you hover over the <a> tag
2. context menu displays
3. you try to move the mouse over to the menu
4. menu disappears
5. you can't click the menu *frustration*

This hopefully avoids showing menus when the user didn't intend to see
them

In this change, I've added it to various links in the list view to get
the sense of how it feels like.

So that parameter definitions can define optional parameters.

(and replaced custom event addition with simpler one from Prototype)

[FIXED JENKINS-12302] Refactor anonymout class for loading groovy script into separate class as static block (due to inheritance of outer class from CLICommand) initialization leads to NPE (namely in Jenkins.getInstance Jenkins.getInstance().getPluginManager())

On iptables protected system, full time out can take 30 secs, which is
too long.