šø macros: Allow expressions for values of `service` attributes
Instead of only allowing string literals, allow any expression. This is
mainly to allow use of `env!` for these constants.
Fixes #237.
š core: downgrade socket read warnings to debug
Once a client goes away after a call, a warning will be emitted while
the future of the still-existing connection is being polled because the
client went away.
To avoid unnecessary noise, this should be a debug.
Signed-off-by: Raito Bezarius <masterancpp@gmail.com>