acpi - add an error dialog for systems with acpi but no acpid

we never told users before. we should. this would sovle some issues
i've seen of people saying that closing the lid doesn't work with e
and they didn't install acpid (even though packages often recommend it).

this improves usability.

src/bin/e_acpi.c

@@ -132,7 +132,16 @@ e_acpi_init(void)
    E_EVENT_ACPI = ecore_event_type_new();
 
    /* check for running acpid */
-   if (!ecore_file_exists("/var/run/acpid.socket")) return 1;
+   if (!ecore_file_exists("/var/run/acpid.socket"))
+     {
+        if (ecore_file_exists("/proc/acpi"))
+          e_util_dialog_show(_("Error"),
+                             _("You seem to have an ACPI based system, but<br>"
+                               "<hilight>acpid</hilight> does not seem to be running or<br>"
+                               "contactable. Perhaps enable the <hilight>acpid</hilight><br>"
+                               "service on your system?"));
+        return 1;
+     }
 
    /* try to connect to acpid socket */
    _e_acpid = ecore_con_server_connect(ECORE_CON_LOCAL_SYSTEM,