Use unique localStorage name for each form's data set

Creates a unique, namespaced array for each form’s data set. Results in
less clutter in localStorage, and allows for fields in different forms
to use the same name with creating conflicts.

This version breaks stored data from version 1.0. Forms without a
unique ID will be saved as `formsaver-anonymous`, and multiple forms
without IDs will overwrite each others’ data.
Delete form-saver copy.js
Changed `.hide-no-local-storage` to `.hide-no-js`
Fixed namespacing for forms without an ID

Uses URL as name for form without an ID, and generates a console
warning.
Updated version number and readme file
Fixed typo in console warning
Merge branch 'wip-1'