Revert "Revert stylesheet changes for propagate button"

This reverts commit 3834eee5e99f24dc12ab8f074efb90c6506206a8.
Move addPropagateButton template to forms.xsl to prevent broken dependency

Originally this template was in DryadUtils.xsl, which is imported by Mirage.
However, the Paypal.xsl theme does not import DryadUtils.xsl, and forms.xsl was referencing a template that didn't exist.

The template has been moved to the same file that calls it, so that other themes don't depend on DryadUtils.
Test to confirm /submit-paypal-checkout is responding

Detects bug that caused https://trello.com/c/56AM5JBv/224-urgent-finalize-button-redux
Remove unused imports
Merge pull request #603 from datadryad/propagate_metadata

Propagate Metadata Feature