Move ftplugin to autoload; ftplugin makes no sense

- "phpcomplete" is not a filetype and therefore this does not get
  sourced properly. This should be in "autoload", not "ftplugin"
fix issue #7

- The complete function changes window in a way that breaks vim unless
  you are completing from the bottom-right-most window.

- Resolved by remembering the window we started in and restoring that
  location.

- This is dirty and hackish and should be accomplished without
  generating new windows.