Use Castle.Windsor for logging.

This has the advantage of using an IoC container instead of doing all
the work manually.
refactoring of message class

(cherry picked from commit d5f004d2abd14bc2b4acb61664f4c14e1d75470a)

Conflicts:
	src/Helpmebot/Commands/Access.cs
Merge branch 'castle'

Conflicts:
	src/Helpmebot/Commands/Access.cs
Message service