V4 updates (#210)

* update pxt.json files

* Fix button event enums

fixes https://github.com/microsoft/pxt-calliope/issues/206

* Fix Safari CSS Rule for iOS app

fixes https://github.com/microsoft/pxt-calliope/issues/205

* aprove preffered repos

should fix https://github.com/microsoft/pxt-calliope/issues/167

libs/bluetoothprj/pxt.json

@@ -1,10 +1,10 @@
 {
     "name": "{0} block",
+    "description": "",
     "dependencies": {
         "core": "file:../core",
         "bluetooth": "file:../bluetooth"
     },
-    "description": "",
     "files": [
         "main.blocks",
         "main.ts",