Log level can be changed after log helper's creation
Changed 3 update frame messages to 1 (until the moment when different update frames will be really needed)
Some new log messages
Plugins manager sets the name of plugin before installing it
Dummy subsystem synchronized with the rest code base
Remove console logger listener before logger's subsystem destruction
Merge branch 'master' of github.com:Eaglegor/UnknownEngine into OgreRenderSubsystem