SQLite can return `SQLITE_BUSY` errors when it's doing too many things at
the same time. This is now improved a bit by setting a 5-second timeout,
during which the SQLite driver will wait for the database to become
available. If that doesn't happen, Flamenco Manager will return a
`503 Service Unavailable` response so that the client knows to back off
a little.
Flamenco Manager now has a "storage path" config option, which will be
used by Shaman if enabled. Now the `{jobs}` implicit variable will always
exist, its value depending on whether Shaman is enabled or not.
This allows the Blender add-on to submit jobs at path
`{jobs}/path/file.blend`. Due to the nature of the system, the add-on
doesn't know (and shouldn't know) where exactly the Manager has its
Shaman storage.
- Addon switches between filesystem-packing and Shaman-packing
automatically, depending on whether the Manager has Shaman enabled.
- Actually using BAT for Shaman packing.
It doesn't work though, some error occurs when receiving Shaman response
from the Manager in the Addon.
This introduces some more conceptual changes to Shaman. The most important
one is that there is no longer a "checkout ID", but a "checkout path".
The Shaman client can request any subpath of the checkout directory,
so that it can handle things like project- or scene-specific prefixes.
The add-on code was copy-pasted from other addons and used the GPL v2
license, whereas by accident the LICENSE text file had the GNU "Affero" GPL
license v3 (instead of regular GPL v3).
This is now all streamlined, and all code is licensed as "GPL v3 or later".
Furthermore, the code comments just show a SPDX License Identifier
instead of an entire license block.
The build chain got a bit confused when doing things from scratch, as
`test_support.go` was used in the non-test builds. Renaming it to
`support_test.go` was the easiest way to avoid that.
The task status change → job status change code is a direct port of the
Flamenco Server v2 code written in Python.
There is no job status change → task status changes logic yet, and the
tests are also far from complete.
Some parts of Flamenco had a Command consist of "name + settings", and
other parts used "type + parameters" (with the same semantics). This is
now unified to "name + parameters".
