Adding support for Swift REPL via comint-mode
Merge pull request #21 from ap4y/feature_repl

Feature REPL
Clean up after pull request

- Merge custom vars into a single group
- Update docstrings
- Rename vars
- Add autoload directive to `swift-mode-run-repl`
Add swift repl commands to mode map
Update readme

- Refill
- Add js-comint acknowledgement
- Style tweaks
- Update install instructions
fixup! Add swift repl commands to mode map
Replace if not with unless
repl -> REPL
Remove redundant hook definition
Add mode menu
Use a more descriptive map variable name inside its definition
Remove redundant autoload
Extend a bit installation instructions for package.el