bugs: restructure dir for website generation
move bug to wishlist

It's a missing feature, not a bug in the existing implementation.
html/gen: create parent directories of target
html/gen: don't warn for files under bugs/
html/gen: only lowercase paths if they are all-caps
bugs: wishlist edits
html/gen fix: don't change case in directory names
html/gen cont, .xhtml
add 'add' and 'array_sum'
allow the_method to pass arguments from 'context'
bugs: edit
html/gen: parse cost markers
add 'array2hash_group_by'
html/gen: generate list of bugs/wishlist in Issues
html/gen: fix handling of /<bugname>/index.md
html/gen: fix broken handling of "README" case
html/gen: add unicode arrow
css: add formatting for costlist
html/gen: add Type column to buglist
bugs: edits