compilation-mode needs a tool-bar

[Dan Nicolaescu]

It seems pretty obvious that compilation mode needs a tool-bar.  Users
are used to tool-bars for this functionality from other environments,
and it's actually pretty useful

It could have buttons for:
   -next error
   -previous error
   -stop compilation
   -restart compilation
  Or maybe even better the "stop" button would turn into "restart" when
  the compilation is over.

Please add this.

Thanks!

[I won't volunteer for this, I've had "Emacs.ToolBar: 0" in .Xdefaults
from the day I first saw the tool-bar]