rb_info plugin and button,action+context name helper

rb_info is just a test plugin

just some info from the running rockbox install

the real star here is the generator scripts to make actions_helper.c and button_helper.c

Change-Id: I23f7bbdae3f2cffca2490c4df40bb13b0b5d5064

apps/action.h

@@ -129,6 +129,7 @@ enum {
     CONTEXT_USB_HID_MODE_PRESENTATION,
     CONTEXT_USB_HID_MODE_BROWSER,
     CONTEXT_USB_HID_MODE_MOUSE,
+    LAST_CONTEXT_PLACEHOLDER,
 };