gradle build: refactor cleanFitnesseroot
Call git directly instead of forwarding to command interpreter
Check keepTests property in gradle build
to allow skipping purge of uncommited acceptance tests
Update contrib docs about keepTests property
Merge pull request #313 from dbfit/keep-uncommitted-acceptance-tests-on-gradle-build

Add an option to keep uncommitted acceptance tests on gradle build
Improvements to dbfit-teradata adapter
Merge pull request #316 from dbfit/pmsoftware-master

Improvements to dbfit-teradata adapter
Oracle tests: delete duplicate BulkInsert test

This test is already included in the `CoreTests`.

Resolves #315.
Merge pull request #317 from dbfit/delete-duplicate-oracle-bulkinsert-test

Oracle tests: delete duplicate BulkInsert test
Merge upstream changes