Log Message:
slony1: updated to 2.2.7

2.2.7
- Fix warning with flex 2.6+
- Fix compile errors with PG11
- Fix bug in with regex in 'set add sequence' when
  specifying the sequence as a regular expression.
  It was not being escaped properly
- Add support to Slonik to specify the share direcotry
  using the environment variable SLONY_SHARE_DIR
- Add slon config setting remote_listen_serializable_transactions
  to use read committed instead of read-only-serializable deferable
  transactions(default true)
- Add slon config setting enable_version_check to disable
  the slony version check that ensures all nodes run the
  same slony version (default true, version check enabled)