Mode editor upload to server

I want to use the mode creator to create my own mode but there seems to be no way to make changes in the mode creator persistent aside from copy'n'pasting from the mode creator into another editor, which is silly.
So I added PUT support to static.py and corresponding buttons and Ctrl-S bindings to the 2 panels of the mode creator.
With these changes in place one can start static.py with e.g.

./static.py --puttable=lib/ace/mode/newmode_highlight_rules.js,demo/kitchen-sink/docs/newmode.rudl

and then work in the mode editor with Ctrl-S/Upload-Button saving directly to disk.
I improved the usability of the buttons.

1) I changed the name from "Upload" to "Save" because that verb transports the idea of saving to the local disk as opposed to some remote server (e.g. ace.c9.io).

2) I translate the 405 Method not allowed response to a verbose message:
"Write access to this file is disabled. To enable saving your changes to disk, clone the Ace repository and run the included static.py web server with the option
--puttable='lib/ace/mode/*_highlight_rules.js,demo/kitchen-sink/docs/*'

I believe with these changes it makes a lot of sense to keep the buttons even in the instance served on ace.c9.io. Without the buttons it is non-obvious to people that there exists an easy way to use the mode creator as a regular editor with direct saving to disk. Besides, the buttons also serve as change indicator. They are greyed out while the document is unmodified and only become enabled when the document is changed. Their changing back to disabled after a save also signals the success of the PUT. Last but not least I have found Ctrl-S to work unreliably. Sometimes the browser will intercept it and pop up its own Save Page dialog.

So if you insist on removing the buttons, you will have to do so yourself after pulling. I can't prevent that. But I'm not willing to give them up.