Patch to fix alt tag issues in images in kupu in lenya 1.2.3

["Mike M." <le...@mordent.com>]

Hi,

I don't know if this will help anyone but we had some problems with alt tags and
images in our lenya implementation (1.2.3).  We fixed them and wanted to
contribute the fixes back to the community.

This patch fixes some broken image handling in kupusave.xsl as well as sets the
default alt text of an image to the title you gave it when you imported the
asset (it used to use the wrong field so it always ended up blank).

Good luck,
-mm