small fixes

Hello

played a bit around with it. Got it to compile, but when trying to edit a picture I run into problems. I got stuck while trying to fix cmsAddTag, which should perhaps be cmsWriteTag (http://www.littlecms.com/LittleCMS2.5%20API.pdf), but that didn't work either, since f-spot complained that it can't write a new copy of the file, but it stopped crashing.

Anyway keep in mind that I have no clue about mono, so I'm not really sure what I'm doing ;)

HTH

Arun