Using different hash algorithm in purple_util_get_image_checksum()

[Richard Laager]

On Wed, 2009-07-01 at 01:29 -0700, Mark Doliner wrote:
> Vijay from Meebo tells me that he seems to
> remember the sha-1 implementation in glib 2.16 is much faster than the
> one in our cipher.c.

If this is true and it would be possible, it'd be nice if we just called
that from our cipher API when libpurple is built against glib >= 2.16.

Richard