This is a modified version of patch #2995

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

source/blender/src/writeimage.c

@@ -60,6 +60,9 @@ int BIF_write_ibuf(ImBuf *ibuf, char *name)
 	else if ((G.scene->r.imtype==R_BMP)) {
 		ibuf->ftype= BMP;
 	}
+	else if ((G.have_libtiff) && (G.scene->r.imtype==R_TIFF)) {
+		ibuf->ftype= TIF;
+	}
 	else if ((G.scene->r.imtype==R_TARGA) || (G.scene->r.imtype==R_PNG)) {
 		// fall back to Targa if PNG writing is not supported
 		ibuf->ftype= TGA;