adds the LinkMonitor, which can monitor changes
on interfaces, if netlink lib is not available
link-request-interval now polled by LinkMonitor from LinkManager
added necessary comments, removed unnecessary comments
fixed value in ibrdtnd.con
changed LinkManager/LinkMonitor pointers into references
adapted LinkMonitor-constructor
renamed LinkManager variable
fixed Conditional and its signal
set intitial link-request-interval to 1000
restored order of execution in Nativedaemon
Merge pull request #6 from dgoltzsche/goltzsch/LinkMonitor

Add LinkMonitor to all LinkManager classes without automatic detection of added/removed addresses.