XMP Import Patch

[Bengt Thuree <bengt thuree com>]

Hi Guys

Ok, hopefully this is one of the last versions of this patch.
Warrens suggestion of a Hash table has been implemented. Not to straightforward
with bags (string, or string[] and should also have string[][] but have not
done that)

Ruben: I removed those prepared calls.

Ben: I added a "AddImportRootTagIfNotExist" function, which should make it a
bit easier to read.

I verified the total number of tags imported before and after these changes,
and they were the same (tested 700+ photos) 

/Bengt

P.s. 
Bug link
http://bugzilla.gnome.org/show_bug.cgi?id=342137

Patch link
http://bugzilla.gnome.org/attachment.cgi?id=70310&action=view

Icon
http://bugzilla.gnome.org/attachment.cgi?id=69565&action=view 
Put this one in the icon directory, and do a normal make + make install