Added phing plugin

plugins/phing/phing.plugin.zsh

+_phing_does_target_list_need_generating () {
+  if [ ! -f .phing_targets ]; then return 0;
+  else
+    accurate=$(stat -f%m .phing_targets)
+    changed=$(stat -f%m build.xml)
+    return $(expr $accurate '>=' $changed)
+  fi
+}
+
+_phing () {
+  if [ -f build.xml ]; then
+    if _phing_does_target_list_need_generating; then
+      echo "\nGenerating .phing_targets..." > /dev/stderr
+      phing -l |grep -v ":" |grep -v "^$"|grep -v "\-" > .phing_targets
+    fi
+    compadd `cat .phing_targets`
+  fi
+}
+
+compdef _phing phing