Add basic LSP support

Still needs to be documented, but includes support for the following
languages:

+ C/C++/ObjC
+ Go
+ Java
+ Javascript
+ OCaml
+ PHP
+ Python
+ Ruby
+ Scala
+ Swift
+ HTML/CSS

Relevant to #460, #716, #1186

modules/tools/lsp/autoload.el

@@ -0,0 +1,7 @@
+;;; feature/lsp/autoload.el -*- lexical-binding: t; -*-
+
+;;;###autoload
+(defun +lsp|init ()
+  "Enable LSP as late as possible, to allow users to customize it via file or
+dir local variables."
+  (add-hook 'hack-local-variables-hook #'lsp nil t))