v7.15.1-rc.0

Changelog

• a0cb7ac Allow configuration of origin connection throttling
• 1051f21 Don't stat /dev/null
• a5687d3 Isolate config of citest.sh
• f24911d Re-implement stat check, but only for files (and not directories)
• 7305356 Remove stat check as it doesn't work with directories
• ef11005 Sanity check received size and on-disk size for client GETs
• f67d716 Set XDG_CACHE_HOME for multiuser origins
• 5bdcc38 Tidy up whitespace in xrootd-origin template
• dcd07b9 Update for coding style
• 3561fb6 Updated version
• 66376f1 Validate concurrency params before starting origins/caches