gitignored build and dist, added date template with help_text
added help_text to remaining form_snippets
updated README
added date widget and help_text examples to camel_photos.json
typos
changed date example in camel_photos.json to use isodate validator
updated README re using the isodate validator for fields using date.html form snippets
added tests for date fields
Updated README validator section with links to available validators fron CKAN
Merge pull request #12 from florianm/7-date

#7 date and #9 helptext