StateViewWeaver crashes with NPE

[Matthias Schoettle]

When weaving fault_tolerance/Transactions/Recovering.ram the StateViewWeaver crashes in StateViewWeaverUtils line 211 with a NullPointerException.

This occurs when the searched signature is coming from an extended aspect and is therefore not contained in the weaving information.

In that case, the reference to the signature should remain unchanged as it will be taken care of when the extended aspect is woven.

[Matthias Schoettle]

Resolves #260: Adds a check to make sure the wovenOp list is not null and if so, keeps the current reference of the signature.

Additionally fixes a small mistake when copying the state view, which used the wrong classifier (not the woven one).

→ <<cset c2c3668be853>>