all: Add package runtimeos for runtime.GOOS comparisons
I grew tired of hand written string comparisons. This adds generated
constants for the GOOS values, and predefined Is$OS constants that can
be iffed on. In a couple of places I rewrote trivial switch:es to if:s,
and added Illumos where we checked for Solaris (because they are
effectively the same, and if we're going to target one of them that
would be Illumos...).
Consistently use double dashes and fix typos -conf, -data-dir and
-verify.
Applies also to tests running the syncthing binary for consistency.
* Fix mismatched option name --conf in cli subcommand.
According to the source code comments, the cli option flags should
mirror those from the serve subcommand where applicable. That one is
actually called --config though.
* cli: Fix help text option placeholders.
The urfave/cli package uses the Value field of StringFlag to provide a
default value, not to name the placeholder. That is instead done with
backticks around some part of the Usage field.
* cli: Add missing --data flag in subcommand help text.
The urfave/cli based option parsing uses a fake flags collection to
generate help texts matching the used global options. But the --data
option was omitted from it, although it is definitely required when
using --config as well. Note that it cannot just be ignored, as some
debug stuff actually uses the DB:
syncthing cli --data=/bar --config=/foo debug index dump
This removes the switch for using a Badger database, because it has bugs
that it seems there is no interest in fixing, and no actual bug tracker
to track them in.
It retains the actual implementation for the sole purpose of being able
to do the conversion back to LevelDB if anyone is actually running with
USE_BADGER. At some point in a couple of versions we can remove the
implementation as well.
