index support

[Matthias Clasen <maclas gmx de>]

I have attached a patch adding index support to gtk-doc to 

http://bugzilla.gnome.org/show_bug.cgi?id=92861

Here is what I wrote in the bug:

Here is a patch to make gtk-doc support index creation. In order to
use it, simply add an <index/> element at the proper spot in your
driver document. gtk-doc emits two index entries per symbol, one
primary one and a secondary one under the symbol type, e.g. the
G_LIKELY() macro will produce an entry "G_LIKELY()" under "G" and an
entry "macros, G_LIKELY()" under "M".

Do you think this is a good idea ?

Matthias