scons: update to 4.0.1

Cleaned up Makefile to standards.

Replaced HIDDEN with BUILDONLY. It's more descriptive.

Added PKG_HOST_ONLY. This is a host only package.

Added HOST_BUILD_PARALLEL.

Added URL for uscan.

Added patch to fix library searching.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

devel/scons/patches/002-fix-import-path.patch

@@ -0,0 +1,10 @@
+--- a/scons.py
++++ b/scons.py
+@@ -56,6 +56,7 @@ if script_path in sys.path:
+     sys.path.remove(script_path)
+ 
+ libs = []
++libs = [os.path.join(os.path.dirname(script_dir), 'lib', 'scons')]
+ 
+ if "SCONS_LIB_DIR" in os.environ:
+     libs.append(os.environ["SCONS_LIB_DIR"])