Bug 14963: Add the ability to suggest purchase on existing title

Bug 14963: Add the ability to suggest purchase on existing title

This patch adds the ability to create a new purchase suggestion from an
existing title. This will prevent the creation of bibliographic records
that already exist in the catalogue. Also it will ease the process
during acquisition.

Test plan:
- Login at the OPAC and go to the detail of a bibliographic record.
- Note that there is a new link "New purchase suggestion for this title"
on the right of the screen
- Please suggest an other icon if that one is not appropriated
- Click on it and submit your new suggestion
=> You should not get the confirmation screen (introduced by bug 14973)
warning you that the title already exists.
- Login staff side and order from this suggestion.
- Receive items and confirm that a new bibliographic record is not
created.

Sponsored-by: BULAC - http://www.bulac.fr/
Signed-off-by: Séverine QUEUNE <severine.queune@bulac.fr>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>