Renames LogBufferMonitor to ByteCounterMonitor

It is clear after some usage that log buffer monitoring is really
 a case of counting bytes, functionality that needs to be replicated in
 other places as well. It makes sense therefore to have LogBufferMonitor
 strictly count bytes, rename it to ByterCounterMonitor and reuse it
 where necessary.
Removes support for HA protocols from versions 1.5.3 and 1.7

Ha protocols from versions 1.5.3 and 1.7 are no longer supported for
 rolling upgrades. Hence they are no longer necessary to be present
 in the codebase.
Introduces usage of ByteCounterMonitor in XaLogicalLog operations

LogExtractor now updates a ByteCounterMonitor with bytes read while
 extracting transaction entries from a log
XaLogicalLog updates a ByterCounterMonitor when deserializing
 prepared transactions from disk for sending over the network
XaLogicalLog now updates a ByteCounterMonitor when deserializing
 a transaction stream over the network
Introduces monitoring in network HA operations

BlockLogBuffer now updates a ByterCounterMonitor with the bytes it
 writes to the underlying buffer. This way all operations that
 serialize transactions to the network can be monitored.
Master and Client instances now make use of that BlockLogBuffer
 for streaming results and transactions.
Introduces a RequestMonitor which logs HA requests. It supports
 request context via a hashmap which can be set to contain various
 information about the request logged.
Client and Server now update a RequestMonitor with requests sent
 and received, respectively.