Remove timers from Mainloop

Timers are currently unused, slightly buggy (for example timeout doesn't
get updated correctly), and unneeded in the current form. Confd will
have timeouts in more simple fashion, and is not a mainloop user
anyway.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>