Update Chameleon Internationalization to comply with Pyramid narrative docs

[stevepiercy]

Update this:
http://pyramid-cookbook.readthedocs.org/en/latest/templates/chameleon_i18n.html

to be compliant with this:
http://docs.pylonsproject.org/projects/pyramid/en/latest/narr/i18n.html#working-with-gettext-translation-files

Report in IRC:
"when I run the extract_messages command I get "ValueError: Unknown extraction method 'lingua_python'", if I try changing it to just 'python' I get the same error for 'lingua_xml'"

[wichert]

There are also several questions on stackoverflow related to this.

[J20S]

I am still experiencing the same problem which is "ValueError: Unknown extraction method 'lingua_python".

I followed exactly the instructions provided in
http://pyramid-cookbook.readthedocs.org/en/latest/templates/chameleon_i18n.html.

At first, I get this error: "error: no output file specified". I then added a setup.cfg file to specify the output file (I notice that the setup.cfg is not mentioned at all in the latest documentation), then I got the above error.

Any help is greatly appreciated!

[stevepiercy]

@J20S Do either of these SO answers help?
http://stackoverflow.com/a/30287865/2214933
http://stackoverflow.com/a/13471618/2214933

Maybe the Jinja2 example can be applied to Chameleon?