For consistency, add support for special "last" id to the get one execution API endpoint.
For consistency, add support for special "last" id to the get one
execution API endpoint.

Plexxi/st2,nzlosh/st2,nzlosh/st2,Plexxi/st2,Plexxi/st2,StackStorm/st2,nzlosh/st2,StackStorm/st2,nzlosh/st2,StackStorm/st2,Plexxi/st2,StackStorm/st2