Add indexpages option

This is the easy part of supporting foo/index.mdwn sources for page foo.

Note that if foo.mdwn exists too, there will be a warning about multiple
sources for the same page, and which is used is indeterminate.

indexpages should also cause web based editing to create index source pages
by default; this and other fallout of the option not yet implemented.

0 files changed, 0 insertions, 0 deletions