* Support refactorings through code actions.
- make LspCodeAction work on a selected range, to support extract method
or extract variable refactorings
- properly execute commands returned by code actions
- support workspace/applyEdit requests from server
* Fixes to match the Google VimScript Style Guide
* Refactor handling of requests from server.
Introduce an on_request option in lsp#client#start, that will be called
every time a request is received from a server.
* Use robust operator ==#
* Move apply_workspace_edit to separate file.