Before this patch selfupdate detected ANY build with cmount tag as a build
having libFUSE capabilities. However, only dynamic builds really have it.
The official linux builds are static and have the cmount tag as of the time
of this writing. This results in inability to update official linux binaries.
This patch fixes that. The build can be fixed independently.
This patch modifies the output of `rclone version`.
The `os/arch` line is split into `os/type` and `os/arch`.
The `go version` line is now tagged as `go/version` for consistency.
Additionally the `go/linking` line tells whether the rclone
was linked as a static or dynamic executable.
The new `go/tags` line shows a space separated list of build tags.
The info about linking and build tags is also added to the output
of the `core/version` RC endpoint.
