README: update download link to latest version
SFTP: fix an issue with the stat cache
Merge pull request #403 from terrafrost/stat-cache-fix

SFTP: fix an issue with the stat cache

* terrafrost/stat-cache-fix:
  SFTP: fix an issue with the stat cache
Merge branch 'master' into php5

* master:
  SFTP: fix an issue with the stat cache
  README: update download link to latest version