Static Linux build should include libtiff library

Hi Nir,

one of your trusty beta-testers is back :) I just was too busy the last months, so there were other priorities to handle first...

slskqt: error while loading shared libraries: libtiff.so.4: cannot open shared object file: No such file or directory

Please note that I'm just reporting this to make user's life easier. Though I can fix these things myself, the libtiff v4 ought to be included in the static build to make it run OOTB. (I reckon that in an 18 MB build, this will not blow up the file size too much anyhow! (*grin*))