Merge branch 'debian-merge-024-deb7' into debian-0.2.4-deb7

* debian-merge-024-deb7:
  New upstream version: 0.2.4.27
  Changelog for 0.2.4.27
  Bump 0.2.4 version more places
  Bump 0.2.4 version
  Changes file for bug15601
  Handle empty/zero length encoded intro points more gracefully.
  Treat empty introduction points sections as missing.
  Validate the RSA key size received when parsing INTRODUCE2 cells.
  ... and if we do get multiple INTRODUCE1s on a circuit, kill the circuit
  Block multiple introductions on the same intro circuit.