Revert IDL compiler build flow to Perl, rename 'deprecated'

Source/bindings/scripts/unstable/v8_callback_interface.py

Index: Source/bindings/scripts/unstable/v8_callback_interface.py
diff --git a/Source/bindings/scripts/v8_callback_interface.py b/Source/bindings/scripts/unstable/v8_callback_interface.py
similarity index 93%
rename from Source/bindings/scripts/v8_callback_interface.py
rename to Source/bindings/scripts/unstable/v8_callback_interface.py
index ceb7c99ed5a70e7f591fb6bd24a8a8a9edf623fc..ce487865daa70c4292b72a28c872b1e6c06a52db 100644
--- a/Source/bindings/scripts/v8_callback_interface.py
+++ b/Source/bindings/scripts/unstable/v8_callback_interface.py
@@ -26,7 +26,14 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-"""Generate template values for a callback interface."""
+"""Generate template values for a callback interface.
+
+FIXME: Not currently used in build.
+This is a rewrite of the Perl IDL compiler in Python, but is not complete.
+Once it is complete, we will switch all IDL files over to Python at once.
+Until then, please work on the Perl IDL compiler.
+For details, see bug http://crbug.com/239771
+"""
 
 from v8_types import cpp_type, cpp_value_to_v8_value, includes_for_type
 from v8_utilities import v8_class_name