Allow non-empty falsy values for UDF choices, Fixes #950
Add USDA Grant info
Merge pull request #956 from maurizi/fix/950/allowZeroForUDFChoices

Allow non-empty falsy values for UDF choices, Fixes #950
plot -> planting site
Use more consistent test case names
Remove unused requirement
Fix bad delete url from tree detail page

Tree deletion was working from a plot detail url but broken from a tree detail url.
Allow 'administrator' role to delete objects