Redis Cache By Xon 2.18.3

• Support zstd compression
• New retry_reads_on_master option, when a read to the slave-redis instance fails (ie due to the redis instance still loading data), reads will fail-back to the master instance.
• Confirm php 7.3 compatibility for pure-php redis connector
• Compat bugfix for phpredis-v3 for exists() function. phpredis-v3 returns a bool, credis/phpredis-v4 return an int, this ensures all backend redis connectors return the same type for the exists function.

• Due to an XF2.0.10 bug, the previous 2.1.6 zip was not compatible with some zip extractors

• Make AdminCP redis info block collapsable

• Ensure cached css entries expire after ~1 hour like stock XenForo caching does.
  • On install, all existing css entries will be purged from the configured redis instance

• Tweak execution order of class extensions/template modifications/etc to provide predictable ordering
• Add LICENCE and README.MD to redistributable.

• If decompression of fetched content fails, just fail the cache get request. This should be a safe trade-off as if the key returns nothing XF stack should regenerate it.
  • Makes changing compression type a cache flush rather than rendering the site useless until Redis is manually flushed.

• Support configuration-less usage to match built-in Redis provider.
  • If no server has been configured try localhost

• Remove debug code injecting multiple slaves
• Fix correctly generating connection to slave for details.
• Report serializer being used (php/igbinary).

• Add redis stats to dashboard, and under Tools -> Redis Info.

• Remove empty options page