Do not propagate regular parameters of closures

The previous commit allowed for the propagation of closure context when nested. This worked a bit
too well as regular closure parameters would be considered as dependencies to be resolved, too,
causing closure references to make lookups on non-existing references in the wrong block.

This commit prevents regular parameters to be propagated. This has been tested on samples with
deeply nested closures.

Squashed commit of the following:

commit 38ab16d2fd9a9fc4a7e11e93f34123e138c8aac0
Author: Julien Ponge <julien.ponge@insa-lyon.fr>
Date:   Wed Apr 10 23:21:26 2013 +0200

    Sounds good

commit c8175fdc75bd50f3eebe26365ef7c3d08bdc2d17
Author: Julien Ponge <julien.ponge@insa-lyon.fr>
Date:   Wed Apr 10 23:18:52 2013 +0200

    Could this be it?

commit c01e34ae1d4e459670ad5cda200c33634334e0a7
Author: Julien Ponge <julien.ponge@insa-lyon.fr>
Date:   Wed Apr 10 22:55:01 2013 +0200

    Seems better....

commit 430d2279df1c20f5159ea7ac6a5dabd5f82db764
Author: Julien Ponge <julien.ponge@insa-lyon.fr>
Date:   Wed Apr 10 16:58:59 2013 +0200

    Traces--

commit 92b3b80629fb5ba21828f53604ed327176322059
Author: Julien Ponge <julien.ponge@insa-lyon.fr>
Date:   Wed Apr 10 16:23:39 2013 +0200

    Adding references is useless

commit 668094cdcbef3532d02f0720e1f5fc2d3095106d
Author: Julien Ponge <julien.ponge@insa-lyon.fr>
Date:   Wed Apr 10 15:36:56 2013 +0200

    A pathological case

commit da071d0777e2dc6a2548ba1d81b969a2c79efee5
Author: Julien Ponge <julien.ponge@insa-lyon.fr>
Date:   Wed Apr 10 14:59:31 2013 +0200

    Debug in progress

commit 1b257eaee7465de2967dd46cb43b323d29bb81aa
Author: Julien Ponge <julien.ponge@insa-lyon.fr>
Date:   Wed Apr 10 13:06:41 2013 +0200

    Bug: parameter names shall not be propagated