eager load on the same table twice with extra bind params gets screwed up

[Mike Bayer]

our resident eager loader abuser, John Yang, found this one, which I adapted into a simple test case. the eager load against the same mapper twice via two different association tables fails, when the secondary mapper joins to another mapper with a join condition that has bind params. seems bind params arent getting the advantage of the "aliasization" of the SQL.

[Mike Bayer]

this is actually just a small thing where the BindParamClause object used for the criterion was not being copied, therefore there would only be one BindParam object when there should have been two. BindParamClause properly copies itself upon copy_container() for a clause.

changeset: 1044

[Mike Bayer]

er, thats changeset:1044