create branch 2.6

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branch : 2.6
Wrong usage of "or" instead of "|" in PYSON of Trigger.on_time
(grafted from 2ccefea465fdf1354f9d2ca3ff18790f7dcdf6fe)

--HG--
branch : 2.6
extra : source : 2ccefea465fdf1354f9d2ca3ff18790f7dcdf6fe
Prepare release 2.6.10

--HG--
branch : 2.6
Added tag 2.6.10 for changeset 289c4a741b7c

--HG--
branch : 2.6
Increase version number

--HG--
branch : 2.6
Use the original context in AttributeManager

Because the record instances keep a reference to the context the set_context
method should use the original context unchanged in AttributeManager

review4051002
issue3732
(grafted from 2d5d7b4377a3d9baa15bdd11d216c5555ee1b36d)

--HG--
branch : 2.6
extra : source : 2d5d7b4377a3d9baa15bdd11d216c5555ee1b36d