Log Message:
Update OpenGoo package to 1.5.1.

OpenGoo 1.5.1 has just been released. Several bugs from version 1.5
were fixed forq this release, including:

- Tags permissions. Now a user can only see tags applied to objects
  that the user can view.
- Some milestones were showing in wrong workspaces.
- Custom properties defined in Administration are now searchable.
- Memory exhausted error when rendering repetitive tasks with an old
  date in the calendar.
- Fatal error when copying a milestone.
- Fatal error "undefined function saveFileAttributes" when uploading a \ 
file.
- Fixed the permissions control when editing a workspace's permissions.
- Fixed a small rendering problem with invited users in event edition.
- Fixed error when sending emails to empty recipients.
- Fixed default user preferences' rendered value.
- Fixed a rendering problem in comments and descriptions that would skip
  a character before an email address or link.
- Tags query was using a hardcoded 'og_' table prefix.
- Translate OpenGoo tool now includes subfolders of language folders.
  Checklang also improved.
- Files of type audio/mp3 are now correctly identified as MP3.
- Updated langs.