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

.gitignore

@@ -1,9 +1,19 @@
+.idea/
 node_modules/
+
 /src/scripts/
 /build/
 /build-copy/
 /logs/
 /settings/
-.idea/
 
-/config.json
+/tools/
+
+/src/ts/generated/*
+!/src/ts/generated/gamepad-template.ts
+
+/assets/images/pony.png
+/assets/images/pony2.png
+/assets/images/pony2a.png
+
+/config.json