Rename the "path" argument to "name" if it refers to a page name (i.e.
a path) or "fp" if it refers to a filepath.
Don't escape Page.Name when ready to render a HTML template because in
some case this means unescaping in functions.
New method isHiddenName to replace ad-hoc checks for "." prefixes and
the like.
When looking for hidden files, one needs to check whether the base
name of the path starts with a period. Sadly, a few places checked the
path itself, which only makes sense in the root directory.
