Remove bin lookup in conf sample generator

As of 584b2f, the bin directory has been removed.
No longer need to handle bin/

Change-Id: Ic5013cd27d7e420a6a01d207546f7ac0258d62d1
Add unique constraints to Cell.

In documentation: "name: Name of the current cell. This must be
unique for each cell"
Added unique constraint 'uniq_cell_name0deleted' ('name','deleted')
to Cell model and migrate sripts.
Added new exception `CellsExists`. Updated cell_create() in db.api.
Tests updated respectively.

blueprint db-enforce-unique-keys

Change-Id: Ib76e167089cb4756e4438613b49013ebf0874afe
Make NovaObject support extra attributes in items()

An object could define a field as a property, which needs to get
included in items() and iteritems() for dict compatibility.

Related to blueprint unified-object-model

Change-Id: I2ca665e70fc6d3c9664ae7a74dffd99a56f6a8c1
Merge "Add unique constraints to Cell."
Merge "Remove bin lookup in conf sample generator"
Merge "Make NovaObject support extra attributes in items()"
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp