* Major refactoring of the protocol layer to support this work.
* Fixed protocol issue that was preventing ssh errors (especially connect) from being logged.
On some systems the JSON->encode() function was adding a linefeed and on others it was not. This was causing regression test failures in in the test logs and may have also been inconvenient for users.
* Removed dependency on CPAN packages for multi-threaded operation. While it might not be a bad idea to update the threads and Thread::Queue packages, it is no longer necessary.
* Added vagrant test configurations for Ubuntu 12.04 and CentOS 6.
* Modified wait backoffs to use a Fibonacci sequence rather than geometric. This will make then grow less aggressively while still giving reasonable wait times.
* More options for regression tests and improved code to run in a variety of environments.
* Removed pg_backrest_remote and added the functionality to pg_backrest as remote command.
* Added file and directory syncs to the File object for additional safety during backup/restore and archiving. Suggested by Andres Freund.
* Support for Perl 5.10.1 and OpenSSH 5.3 which are default for CentOS/RHEL 6. Found by Eric Radman.
* Improved error message when backup is run without archive_command set and without --no-archive-check specified. Found by Eric Radman.
* Moved version number out of the VERSION file to Version.pm to better support packaging. Suggested by Michael Renner.
* Replaced IPC::System::Simple and Net::OpenSSH with IPC::Open3 to eliminate CPAN dependency for multiple distros.
Replaced IPC::System::Simple and Net::OpenSSH with IPC::Open3 to eliminate CPAN dependency for multiple distros. Using open3 will also be used for local processes so it make sense to switch now.
Also stopped replacing FORMAT number which explains the large number of test log changes. FORMAT should change very rarely and cause test log failures when it does.
More separation of the protocol and remote layers than was done in issue #106.
Settings are passed to the remote via command-line parameters rather than in the protocol.
* IMPORTANT NOTE: This flag day release breaks compatibility with older versions of PgBackRest. The manifest format, on-disk structure, and the binary names have all changed. You must create a new repository to hold backups for this version of PgBackRest and keep your older repository for a time in case you need to do a restore. The `pg_backrest.conf` file has not changed but you'll need to change any references to `pg_backrest.pl` in cron (or elsewhere) to `pg_backrest` (without the `.pl` extension).
* Add info command.
* More efficient file ordering for backup. Files are copied in descending size order so a single thread does not end up copying a large file at the end. This had already been implemented for restore.
* Logging now uses unbuffered output. This should make log files that are being written by multiple threads less chaotic. Suggested by Michael Renner.
* Experimental support for PostgreSQL 9.5. This may break when the control version or WAL magic changes but will be updated in each release.
* Includes updating the manifest to format 4. It turns out the manifest and .info files were not very good for providing information. A format update was required anyway so worked through the backlog of changes that would require a format change.
* Multiple database versions are now supported in the archive. Does't actually work yet but the structure should be good.
* Tests use more constants now that test logs can catch name regressions.
