app-text/stardict: enable a few default dictionaries

Signed-off-by: Lan Yixun (dlan) <dennis.yxun@gmail.com>
app-text/stardict: add more IUSEs..

Signed-off-by: Lan Yixun (dlan) <dennis.yxun@gmail.com>
app-text/stardict: glib patches, fix thread error

G_CONST_RETURN

/usr/include/glib-2.0/glib/gmacros.h:270

Signed-off-by: Lan Yixun (dlan) <dennis.yxun@gmail.com>