SuperBuild: FFTW: build with --disable-dependency-tracking

dependency tracking if enabled can be an issue later when
loading the dylib. A similar case is seen with sqlite.dylib
custom and installed one. see here:
http://sqlite.1065341.n5.nabble.com/
Mac-OS-Snow-Leopard-32bit-vs-64bit-td53772.html

SuperBuild/CMake/External_fftw.cmake

@@ -36,6 +36,7 @@ else()
             --enable-float
             --enable-threads
             --disable-fortran
+            --disable-dependency-tracking
       DEPENDS ${FFTW_DEPENDENCIES}
       )
 
@@ -57,8 +58,10 @@ else()
             --disable-float
             --enable-threads
             --disable-fortran
+            --disable-dependency-tracking
       )
 
+
     set(_SB_FFTW_INCLUDE_PATH ${SB_INSTALL_PREFIX}/include)
 
   endif()