Project sanity check (#76)

* tslint: CRLF -> LF

* gitignore more build artifacts

* Add proposed .editorconfig

* Allow for "clean" builds

src/ts/generated/ content is still required (sprites.ts,
gamepad-mappings.ts), but src/scripts is not.

* Add --sprites option to production build

* Add note about sprites to README

tslint.json

@@ -36,7 +36,7 @@
 		"no-trailing-whitespace": true,
 		"linebreak-style": [
 			true,
-			"CRLF"
+			"LF"
 		],
 		"max-line-length": [
 			true,
@@ -78,4 +78,4 @@
 			"array"
 		]
 	}
-}
+}