The end year is legally and functionally redundant, and more importantly causes
cherry-pick conflicts when trying to maintain old branches. Use git for history.
A Jcat file can be used to store GPG, PKCS-7 and SHA-256 checksums for multiple
files. This allows us to sign a firmware or metadata multiple times (perhaps
by the OEM and also then the LVFS) which further decentralizes the trust model
of the LVFS.
The Jcat format was chosen as the Microsoft catalog format is nonfree and not
documented. We also don't want to modify an existing .cat file created from WU
as this may make it unsuitable to use on Windows.
More information can be found here: https://github.com/hughsie/libjcat
In the future we'll want to use this flag to signify if the release is an
upgrade, downgrade, below the version-lowest, or if it is locked in some way.
The libxmlb library is much faster to query, and does not require the daemon
to parse the XML metadata at startup. It's a zero-copy mmap design that is more
modern and less clunky.
RSS has reduced from 3Mb (peak 3.61Mb) to 1Mb (peak 1.07Mb) and the startup
time has gone from 280ms to 250ms.
