To enable dynamic tiff support.
I had to fix some of the logic in the fileselect box for icons,
I also expanded the patch to look in various default locations for
a dynamic libtiff.so/libtiff.dll
and look at the env variable BF_TIFF_LIB if it can't find it automatically.
If unable to load the library it prints a message about setting BF_TIFF_LIB
to the console.
I haven't been able to test it on a lot of platforms but hopefully it
will just work ;) I added the files to scons but have not had a chance to
test that as well.
Kent
