Start moving html ext to strict mode compile

Moves the html extension's client code to strict mode and also updates some of the server code. The rest of this migration will requires changes to the *.d.ts files that the server consumes

extensions/html/client/tsconfig.json

@@ -5,6 +5,7 @@
 		"outDir": "./out",
 		"lib": [
 			"es5", "es2015.promise"
-		]
+		],
+		"strict": true
 	}
 }