Had to create dummy init functions at some places since the owner of a package
is the last layer that defines the init function of a package. And a package
can be installed only if it has an owner.
The `swift-mode` REPL bindings have been updated to use a different
naming convention (e.g. a prefix of `swift-mode:` in the CL style).
Typing `, s s` would trigger this error:
```
command-execute: Wrong type argument: commandp, swift-mode-run-repl
```
This change fixes up the command names so that they are usable again
from the leader key.