deploy-ng: Correctly add deploy_libs to sys.path

Now modulefinder will pick up on the Python stdlib C extension modules
in the panda3d whl, and no special path hacks are required.

direct/src/showutil/dist.py

@@ -44,12 +44,6 @@ def find_packages(whlfile):
     return [i for i in filelist if '.so.' in i or i.endswith('.dll') or i.endswith('.dylib') or 'libpandagl' in i]
 
 
-def get_python_ext_module_dir():
-    import cmath
-    import inspect
-    return os.path.dirname(inspect.getfile(cmath))
-
-
 class build(distutils.command.build.build):
     def run(self):
         distutils.command.build.build.run(self)
@@ -95,6 +89,10 @@ class build(distutils.command.build.build):
                 for whl in wheelpaths:
                     sys.path.insert(0, whl)
 
+                # Add deploy_libs from panda3d whl to the path
+                sys.path.insert(0, os.path.join(p3dwhlfn, 'deploy_libs'))
+
+
             # Create runtime
             freezer_extras = set()
             freezer_modules = set()
@@ -141,10 +139,6 @@ class build(distutils.command.build.build):
                     parts = parts[:-2] + parts[-1:]
                     basename = '.'.join(parts)
 
-                if use_wheels and source_path.startswith(get_python_ext_module_dir()):
-                    # Look in panda3d whl instead
-                    source_path = source_path.replace(get_python_ext_module_dir(), '{}/deploy_libs'.format(p3dwhlfn))
-
                 target_path = os.path.join(builddir, basename)
                 if '.whl/' in source_path:
                     # This was found in a wheel, extract it