master: Report changelog application failures in shadow master

Add a new LIZ_MLTOMA_CHANGELOG_APPLY_ERROR message that is sent by
shadow masters to notify the master server about changelog application
problems.

Upon reception of such a message, master dumps metadata and replies. If
the message is about checksum error, the master server also rechecks its
checksum before reply. After this operation shadow master removes its
metadata and downloads a fresh copy from the master server.

Change-Id: Ic706be5016b99b0d29140cef51a8e3c530d3e090
tests: Add test_shadow_checksum_error_recovery

This tests corrupts master's changelog, starts a shadow and verifies
that the shadow detected this corruption and obtained correct metadata
from the master.

Change-Id: Iaa67b7a6afcf7543e3f89a5da2117a27dfd1f39d