[Vala] vapigen ignores .metadata

[Tal Hadad <tal_hd hotmail com>]

I try to create a binding from GNOME official PanelApplet-4.0.gir to libpanelapplet-4.0.vapi.
Vapi generation success, but the header file name is wrong(always "PanelApplet-4.0.h"). I tried to change it 
by adding a new file named "libpanelapplet-4.0.metadata" in the same directory:

PanelApplet cheader_filename="libpanel-applet/panel-applet.h"

But it didn't change anything in the vapi file.
This is my command(based on what you gave me in this mailing list):

vapigen --metadatadir . --pkg gtk+-3.0 --library libpanelapplet-4.0 PanelApplet-4.0.gir

What am I doing wrong?

Tal