6094 Fixing ModAuthority problems

6094 Fixing ModAuthority problems

Only contains db revision to insert new table need_merge_authorities.
You can apply the revision by running
cgi-bin/koha/installer/install.pl?step=3&op=updatestructure. (Will not change
your version while testing.)

Oct 19, 2011: Rebased after functionality patch signoff.

Signed-off-by: Frédéric Demians <f.demians@tamil.fr>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>
Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>