Reset the actor context on runtime initialisation (#2047)
Reset the actor context on runtime initialisation (#2047)

Not reinitialising the context could result in the runtime referencing
an invalid actor if the runtime was stopped and restarted.
Theodus/ponyc,cquinn/ponyc,boemmels/ponyc,dipinhora/ponyc,cquinn/ponyc,kulibali/ponyc,sgebbie/ponyc,cquinn/ponyc,kulibali/ponyc,Theodus/ponyc,Praetonus/ponyc,cquinn/ponyc,jemc/ponyc,boemmels/ponyc,Praetonus/ponyc,Perelandric/ponyc,jemc/ponyc,sgebbie/ponyc,Perelandric/ponyc,Perelandric/ponyc,kulibali/ponyc,ponylang/ponyc,boemmels/ponyc,kulibali/ponyc,ponylang/ponyc,sgebbie/ponyc,CausalityLtd/ponyc,Perelandric/ponyc,sgebbie/ponyc,dipinhora/ponyc,Perelandric/ponyc,boemmels/ponyc,CausalityLtd/ponyc,CausalityLtd/ponyc,Theodus/ponyc,ponylang/ponyc,Theodus/ponyc,Theodus/ponyc,Praetonus/ponyc,jemc/ponyc,dipinhora/ponyc,boemmels/ponyc,sgebbie/ponyc,Praetonus/ponyc