TS-2607: Fix broken linking case for Ubuntu 10.04
TS-2522 Better hook management, and cleanup

This also does

     - Add support for system wide config directory as default
     - Better debug messages (textual hook names etc.)
     - Less overhead on creating TXN hooks
TS-2522 Update the docs with new default conf dir
TS-2611 Add a new S3 auth plugin, experimental/s3_auth
TS-2611 Fix build bustage, thanks Jenkins for being my best friend
TS-2613: Can't turn on attach server session to client from records.config
Fix bug with GzipDefalate transformation
[TS-2609] Rename TOHOST to ORIGIN-HOST for a better name
Merge remote branch 'upstream/master'