backports: pycocci - make the Coccinelle wrapper a standalone tool

backports: pycocci - make the Coccinelle wrapper a standalone tool

This lets us share it for general use as a generic tool, we'll upkeep
it here for now and if Coccinelle picks it up we can drop it and just
require folks to install it.

This lets us use the same solution for standard testing / regular
development and also for backports without any discrepencies.

Cc: Peter Senna <peter.senna@gmail.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Gilles Muller <Gilles.Muller@lip6.fr>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>