added new module_base events and its calls in server
fixed bug in CALL_MODULES_P(participant_leave...
prtection against notifying about hidden participants
initial code of history_module
removed logging about message delivery
added history_module
added get_name function, fixed macro: *this -> this
added get_name definition
corrected misspel in info message
finished base version of history_module
new minor version - v0.6.0-alpha