[XLRSTATS] make use of data binding in SQL queries: fix issue #151
[XLRSTATS] make use of the client 'bot' attribute to identify BOT clients

Previous implementation was checking for the client guid to start with the 'BOT' prefix. The problem of identifying bots correctly has been already solved in another commit in every parser which support bots. XLRstats should not check GUID and leave this job to the parser.
[TESTS] added a test to check XLRstats to correctly handle client bot flag
Merge pull request #211 from FenixXx/release-1.10

[XLRSTATS] Fixed issue #151 + minor change in bots identification