feat: add command.preexec hook

it provides 2 arguments: what the user typed, and the command hilbish
will execute.

golibs/bait/bait.go

@@ -30,6 +30,6 @@ func (b *Bait) throw(name string, args ...interface{}) {
 	b.Em.Emit(name, args...)
 }
 
-func (b *Bait) catch(name string, catcher func(interface{})) {
+func (b *Bait) catch(name string, catcher func(...interface{})) {
 	b.Em.On(name, catcher)
 }

shell.go

@@ -31,6 +31,7 @@ func RunInput(input string) {
 			continue
 		}
 	}
+	hooks.Em.Emit("command.preexec", input, cmdString)
 
 	// First try to load input, essentially compiling to bytecode
 	fn, err := l.LoadString(cmdString)