Fixed wrong indentation in map.html.
I threw in some helper functions for js _expression's.

The hidden default applies to empy objects.
Removed default args in _list/tabulate.

CouchJS apparently runs a lower version of ECMA Script than FF26.0, so the
default arguments have to be rewritten.
Added lib/path.js.

I figured that repeating de/composition of nested properties should go into
this one, before I end up managing it on five different places. From time to
time, I come up with an improvement of these dull RegExps that removes
restrictions to field names.
Pointed a bunch of scripts to lib/path.js.

Except for upload.html, everything looks cleaner now. What a day!!!!