Added cd to active Xcode project to osx plugin

plugins/osx/osx.plugin.zsh

@@ -160,6 +160,15 @@ function pfs() {
 EOF
 }
 
+function xcodeprojdir() {
+  dirname $(osascript 2>/dev/null <<EOF
+    tell application "Xcode"
+      return path of active workspace document
+    end tell
+EOF
+) 2>/dev/null
+}
+
 function cdf() {
   cd "$(pfd)"
 }
@@ -168,6 +177,10 @@ function pushdf() {
   pushd "$(pfd)"
 }
 
+function cdx() {
+  cd "$(xcodeprojdir)"
+}
+
 function quick-look() {
   (( $# > 0 )) && qlmanage -p $* &>/dev/null &
 }