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

docs/blocks/logic/boolean.md

@@ -17,7 +17,7 @@ if (led.point(1,1) && led.point(2,2)) {
 When you compare two Numbers, you get a Boolean value, such as the comparison `x < 5` in the code below:
 
 ```blocks
-input.onButtonEvent(Button.A, ButtonEvent.Down, () => {
+input.onButtonEvent(Button.A, input.buttonEventValue(ButtonEvent.Down), () => {
     let x = randint(0, 5)
     if(x < 5) {
     basic.showString("low");

docs/blocks/logic/if.md

@@ -7,7 +7,7 @@
 If the [light level](/reference/input/light-level) is `< 100`, this code sets the brightness to `255` when the button A is pressed:
 
 ```blocks
-input.onButtonEvent(Button.A, ButtonEvent.Down, () => {
+input.onButtonEvent(Button.A, input.buttonEventValue(ButtonEvent.Down), () => {
     if(input.lightLevel()<100){
         led.setBrightness(255);
     }