Update xterm to v4 (#3830)

* update xterm to 4

* add back webGL addon

* remove ligatures xterm addon, unused atm and does not work with webGL renderer

* update node-pty

* more work on trying to get xterm4 to work

* update xterm to 4.0.2

* move where xterm addon props are assigned

* more updates

* only load webgl addon if webgl is enabled

* fix search function

* remove rendererType setting, the xterm addon does this for us

* use xcode 10.3 on circleci

* fix typo

* revert node-pty bump for now

* use stable versions of the xterm plugins

* fix focus listener

* add windowsMode prop

* move webGL check

* apply tweaks by @GitSquared

* fix resizing issue

* Revert "fix resizing issue"

This reverts commit fce3780.

* apply review suggestions

* change so all addons have separate instances for each terminal

* update yarn-standalone to 1.19

* fix resize problem of split view

by @ivanwonder

* apply review feedback

* fix lint

* add name and version to package.json

* address review feedback

* more review feedback

.circleci/config.yml

@@ -2,7 +2,7 @@ version: 2
 jobs:
   install:
     macos:
-      xcode: "9.2.0"
+      xcode: "10.3.0"
     working_directory: ~/repo
     steps:
       - checkout
@@ -25,7 +25,7 @@ jobs:
 
   test:
     macos:
-      xcode: "9.2.0"
+      xcode: "10.3.0"
     steps:
       - checkout
       - attach_workspace:
@@ -36,7 +36,7 @@ jobs:
 
   build:
     macos:
-      xcode: "9.2.0"
+      xcode: "10.3.0"
     steps:
       - checkout
       - attach_workspace:
@@ -53,7 +53,7 @@ jobs:
 
   release:
     macos:
-      xcode: "9.2.0"
+      xcode: "10.3.0"
     steps:
       - checkout
       - attach_workspace: