Revert "Merge pull request #170 from colemanw/button"

This reverts commit 3f1fb03d5441a1a62755d16a8e8d2277ca0c4a28, reversing
changes made to 4613a64b8536297cbec85bc8a81db8d70a3c90d7.
Added target_contact_id field to project entity and re-ran setup.sh.
Added front-end for target contact. Target contact defaults to the domain organization.
Ported prepopulation of target contact from JavaScript to PHP.
Updated postProcess to handle target_contact_id.

Conflicts:
	CRM/Volunteer/Form/Volunteer.php
Factor out unused enable/disable methods for Project.
Updated Assignment BAO to pass target contact ID from the Project to the activity record.
Clean up bad rebase/cherry-pick.
Added target contact schema change to upgrade.
On volunteer event tab, show/hide target contact field based on status of is_active checkbox.
Updated CRM_Volunteer_BAO_Assignment::retrieve (and hence the VolunteerAssignment get API action)
to return target contact fields as well as to allow filtering by target_contact_id.
Merge pull request #173 from fjg-conflux/project_beneficiary

Add target contacts for volunteer projects