from tapeserver/daemon to common directory

Added preliminary implementation of session's HandlerInterface which will communicate with the former. This class will
replace both TaskWatchDog and TapeServerReporter.
A new protocol buffer class (WatchdogMessage) was created to allow communication between the two.
Added the creation of the drive handler in the tape daemon.
Various minor fixes.

and integrated tpconfig support as well.
Fixed exception losing its initial content after appending with
getMessage() <<

Added a sourced parameter which keeps track of the origin of a parameter.
Ported parsing of configuration files from CASTOR.