versioncontrol_project 5.x-1.3

Only one commit since the previous release, but the API addition is necessary for this patch to work, so this needs to be released now. One or two features are missing for the "final" 5.x release, but we're getting there.

• Remove the UNIQUE (repo_id, directory) as there can be multiple "empty" projects that have (0, '') for those values. Please give update.php a shot.
• Implement the "restrict project creation for users without VCS account" option (including the new API function versioncontrol_project_creation_is_allowed()). node_access() can't be hooked into, so for better usability we might want to get an additional patch into project.inc.
• Properly namespace the versioncontrol_get_projects_for_commit() function so that it's named versioncontrol_project_get_projects_for_commit().