Use default swift pipeline and add extras.

- By default use the default pipeline as shipped with swift.
- Add option SWIFT_EXTRAS_MIDDLEWARE which by default include tempurl
  formpost staticweb bulk to enable extra featuress.
- Clean pids in cleanup_swift Fix bug 1140364.

Rebased

Change-Id: Ida537ae8d3e319a5b84546f82ebf00615f070be1