Add restart to REGISTER-LOCAL-PROJECTS on system-not-found errors

[sjl]

A friend of mine just hit the case described in https://github.com/quicklisp/quicklisp-client/blob/master/quicklisp/local-projects.lisp -- he renamed an .asd file in a local-projects subdirectory and tried to load it, and ASDF signaled a Component :FOO not found error.

It would be nice if Quicklisp could add a restart like [REGISTER-LOCAL-PROJECTS] Refresh the Quicklisp local-projects index and try again alongside all the ASDF restarts that won't solve the problem. This would save a bit of typing and make the solution a lot more discoverable.

[traut]

+1 to that, it would be extremely helpful