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);
     }

docs/blocks/loops/for.md

@@ -7,7 +7,7 @@
 This program will show the numbers 0, 1, 2, 3, and 4 one after another on the LED screen.
 
 ```blocks
-input.onButtonEvent(Button.A, ButtonEvent.Down, () => {
+input.onButtonEvent(Button.A, input.buttonEventValue(ButtonEvent.Down), () => {
     for(let i = 0; i < 5; ++i) {
         basic.showNumber(i)
     }

docs/blocks/loops/while.md

@@ -7,7 +7,7 @@
 The following example uses a while loop to make a diagonal line on the LED screen (points `0, 0`, `1, 1`, `2, 2`, `3, 3`, `4, 4`).
 
 ```blocks
-input.onButtonEvent(Button.A, ButtonEvent.Down, () => {
+input.onButtonEvent(Button.A, input.buttonEventValue(ButtonEvent.Down), () => {
     let index = 4;
     while(index >= 0) {
         led.plot(index, index);

docs/blocks/on-start.md

@@ -5,7 +5,7 @@
 In this example, ``on start`` sets a dimmer brightness on the screen and the button handler shows a string.
 
 ```blocks
-input.onButtonEvent(Button.A, ButtonEvent.Down, () => {
+input.onButtonEvent(Button.A, input.buttonEventValue(ButtonEvent.Down), () => {
     basic.showString("Hello!")
 })
 led.setBrightness(50)

docs/blocks/variables/var.md

@@ -59,7 +59,7 @@ A counter is a great example:
 
 ```blocks
 let counter = 0;
-input.onButtonEvent(Button.A, ButtonEvent.Down, () => { 
+input.onButtonEvent(Button.A, input.buttonEventValue(ButtonEvent.Down), () => { 
   counter = counter + 1;
   basic.showNumber(counter);
 });