Introduce Timer Descriptor class.
Update Makefiles.
Cleanup DBus a bit.
Remove include directive for local_area_network.hpp.
Add some coments about handlig descriptors in Descriptor class.
Throw proper exception.
Update makefiles.
Descriptor remember it's watching settings (redable/writable).
MainLoop::modify_register() gets epoll events via argument.
Descriptor callbacks setters added.
Fix setters names.
Make Descriptor setters public.
New interface for MainLoop for handling Descriptor watching.
Register descriptors in Descriptor constructor.