[Zope] LocalFS problems with @import-ing stylesheets

[Samuel Souk-aloun]

I can confirm the problem, the stylesheet is not rendered from localfs
with firefox

the problem is caused by an incorect http header "text/plain" instead of
"text/css"
I've tried to add a type_map to the LocalFS but the content-type does
not change
so, for me, it is clearly a LocalFS issue

anyone knows how to hardcode this content-type in LocalFS.py ?