Add some documentation for the sandbox block device emulation and fix some issues for the fs test script.

Stefan Brüns (4): Sandbox: document support of block device emulation sandbox: Add "host size" hostfs command for fs test test/fs: strip carriage-return from sandbox output test/fs: replace deprecated "sb" command with "host"

board/sandbox/README.sandbox | 19 +++++++++++++++++++ cmd/host.c | 8 ++++++++ test/fs/fs-test.sh | 42 +++++++++++++++++++++--------------------- 3 files changed, 48 insertions(+), 21 deletions(-)