Features:
* The archive-push command is now partially coded in C which allows the PostgreSQL archive_command to run significantly faster when processing status messages from the asynchronous archive process. (Reviewed by Cynthia Shang.)
Improvements:
* Improve check command to verify that the backup manifest can be built. (Contributed by Cynthia Shang.)
* Improve performance of HTTPS client. Buffering now takes the pending bytes on the socket into account (when present) rather than relying entirely on select(). In some instances the final bytes would not be flushed until the connection was closed.
* Improve S3 delete performance. The constant S3_BATCH_MAX had been replaced with a hard-coded value of 2, probably during testing.
* Allow any non-command-line option to be reset to default on the command-line. This allows options in pgbackrest.conf to be reset to default which reduces the need to write new configuration files for specific needs.
* The C library is now required. This eliminates conditional loading and eases development of new library features.
* The pgbackrest executable is now a C binary instead of Perl. This allows certain time-critical commands (like async archive-push) to run more quickly.
* Rename db-* options to pg-* and backup-* options to repo-* to improve consistency. repo-* options are now indexed although currently only one is allowed.
It would be better if the hostnames were also pg1 and pg2 to illustrate that primaries and standbys can change hosts, but at this time the configuration ends up being confusing since pg1, pg2, etc. are also used in the option naming. So, for now leave the names as pg-primary and pg-standby to avoid confusion.
The host-*-ip variable is created from the id param so the name param can be changed without affecting the host-*-ip variable. If id is not specified then it is copied from name.
Buffering now takes the pending bytes on the socket into account (when present) rather than relying entirely on select(). In some instances the final bytes would not be flushed until the connection was closed.
* Check both doc-path and bin-path for logo.
* Allow PDF to be output to a location other than the output directory.
* Use PDF-specific version variable for more flexible formatting.
1) Error when the same option is defined multiple times in a section using alternate names.
2) Fix logging of invalid command error.
3) Warn when a stanza-only option is in a global section.
Also, make a note to add validation of section names to the check command.
Per review by Cynthia Shang.
The log-level-console option should not be changed in the parent process. Even though it is harmless at the moment, that may not always be true.
Per review by Cynthia Shang.
This provides correct matching in the event there are system-id and db-version duplicates (e.g. after reverting a pg_upgrade).
Fixed by Cynthia Shang.
Reported by Adam K. Sumner.
