Experimental multi-component support

Based on ghcide with

    mpickering/wip/multi-rebase

rebased onto

    pepeiborra/interface-files-0.1.0.0-rebased-once-more

Author: alanz

.gitmodules

@@ -10,5 +10,5 @@
 #     rm -rf path_to_submodule
 [submodule "ghcide"]
 	path = ghcide
-	url = https://github.com/digital-asset/ghcide.git
-	# url = https://github.com/alanz/ghcide.git
+	# url = https://github.com/digital-asset/ghcide.git
+	url = https://github.com/alanz/ghcide.git