Reduce verbosity of shutdownhook

[Desrever Nu]

while shutting down there are some over-verbosity

>> 14:48:24.305 com.nubits.nubot.bot.Global 216 INFO  - move session log dir
>> 14:48:24.305 com.nubits.nubot.bot.Global 142 INFO  - 20150320T144656
>> 14:48:24.305 com.nubits.nubot.bot.Global 146 INFO  - move from: logs/current/20150320T144656 >> to: logs/pastsession/20150320T144656
>> 14:48:24.306 com.nubits.nubot.bot.Global 219 INFO  - create session overview
>> 14:48:24.306 com.nubits.nubot.bot.Global 83 INFO  - read session log
>> 14:48:24.306 com.nubits.nubot.bot.Global 86 INFO  - records found 5
>> 14:48:24.306 com.nubits.nubot.bot.Global 89 INFO  - row session start
>> 14:48:24.307 com.nubits.nubot.bot.Global 93 INFO  - new session object . link: pastsession/logs/current/20150320T144656/all.html
>> 14:48:24.308 com.nubits.nubot.bot.Global 89 INFO  - row session start
>> 14:48:24.309 com.nubits.nubot.bot.Global 93 INFO  - new session object . link: pastsession/logs/current/20150320T144656/all.html
>> 14:48:24.309 com.nubits.nubot.bot.Global 89 INFO  - row session end
>> 14:48:24.309 com.nubits.nubot.bot.Global 89 INFO  - row session start
>> 14:48:24.309 com.nubits.nubot.bot.Global 93 INFO  - new session object . link: pastsession/logs/current/20150320T144656/all.html
>> 14:48:24.309 com.nubits.nubot.bot.Global 89 INFO  - row session end

just leave one important line like the one below:

>> 14:48:24.305 com.nubits.nubot.bot.Global 146 INFO  - move from: logs/current/20150320T144656 >> to: logs/pastsession/20150320T144656