test case names stored as type text

- changed database storage type of test case names from string to text
to allow longer names
custom fields for results and assignments

- added custom field capability to results and assignments
- added ability to delete custom fields from items
- moved find parent functions to helpers file for stencils, test cases,
test plans
- added new link type custom field
- added db migration files for adding custom fields to results and
assignments during setup script
Merge pull request #52 from agramian/allow-longer-test-case-names

test case names stored as type text
Merge pull request #53 from agramian/custom-fields-for-more-item-types

custom fields for results and assignments
Merge pull request #54 from agramian/webapi-v2

version 2 JSON/XML web api
Fixed label for import users page