Properly handle the dependency on libfitsio.a, via a hack.

setup.py

@@ -26,6 +26,7 @@ def initialize_options(self):
         self.cfitsio_dir = 'cfitsio%s' % self.cfitsio_version
         self.cfitsio_build_dir = os.path.join('build', self.cfitsio_dir)
         self.cfitsio_zlib_dir = os.path.join(self.cfitsio_build_dir,'zlib')
+
         build_ext.initialize_options(self)    
         self.link_objects = []
         self.extra_link_args = []
@@ -34,8 +35,6 @@ def finalize_options(self):
 
         build_ext.finalize_options(self)    
 
-        self.force = True
-
         if self.use_system_fitsio:
             # Include bz2 by default?  Depends on how system cfitsio was built.
             # FIXME: use pkg-config to tell if bz2 shall be included ?
@@ -71,6 +70,11 @@ def build_extensions(self):
 
             self.compiler.set_link_objects(link_objects)
 
+            # Ultimate hack: append the .a files to the dependency list
+            # so they will be properly rebuild if cfitsio source is updated.
+            for ext in self.extensions:
+                ext.depends += link_objects
+
         # call the original build_extensions
 
         build_ext.build_extensions(self)