utils: Fix handling LIZ_MATOCL_METADATASERVER_STATUS in wireshark

This message was using 'status' field which caused it to be rendered in
wireshark as:

  LIZ_MATOCL_METADATASERVER_STATUS msgid:1 status:ERROR_ENOTDIR metadata_version:2

This issue is fixes by creating a new field 'serverstatus' with
a proper dictionary.

Also creating a new field 'metadata_version' is not necessary, because an
existing field 'metadataversion' can be used in this message.

Change-Id: I9193cd1f3f7ff42a16bb9e0ab2fffea71de83bee
utils: Fix handling MLTOMA_DOWNLOAD_START in wireshark plugin

Change-Id: I29c54aa694815d6be5ffbe8455b7dd4510a6774d
tests: Increase timeout for test_flushing_changes_to_shadow

Running this test takes more than 20 second in most cases, so the
default timeout may be sometimes too short.

Change-Id: I9cf637f38ba47e937caeaab08c2ab3b85b285ca9
tests: Add depth-wise debugger

Add a debugger that can trace calls executed by tests down to a certain
depth.

Usage: DEBUG_LEVEL=<level> lizardfs-tests ...

Change-Id: Id3672c2ffb728a5d3b6f5d7d423b059432839e32
docs: Add manual page for lizardfs-probe

Change-Id: I39d17d03f74ac605f368cdf7259a05d36f590901
master: Disable registering as shadow until next release

To provide compatibility with mfsmaster 1.6.27 and allow safe upgrade
the new shadow's registering mechanism is temporarily disabled until
mfsmaster supports it too.

Change-Id: Iedc0aaf9d4d42d9b7f0729634d2db4826116521f