Fixing csv upload form

The 2nd argument of make_form is the method. Also, I don't see any point in defining the $multipart variable. Just true as argument is enough. C&P mistake?!
Better CSV validation

When uploading a CSV, check every entry before executing the INSERT. The checks are the same as with the normal add except that no errors are shown.
Merge pull request #316 from HungryFeline/patch-5

Fixing csv upload form