Adds support capistrano multistage completion

plugins/capistrano/capistrano.plugin.zsh

@@ -0,0 +1,11 @@
+# Added `xcap` because `cap` is a reserved word. `cap` completion doesn't work.
+# http://zsh.sourceforge.net/Doc/Release/Zsh-Modules.html#The-zsh_002fcap-Module
+
+func xcap() {
+  if [ -f Gemfile ]
+  then
+    bundle exec cap $*
+  else
+    cap $*
+  fi
+}