Further trimmed RootEntry.
Disabled currently failing unit tests. (now 4 total).

Started morphing the code to accomodate both the move some data structure from OStoreDB to catalogue and shared structures modifications.
Renamed class members using underscode instead of mixed case.
Removed mount criteria from in-memory tape pool representation.
Removed support for path of archive files for in-memory representations.
Removed all but maxDrives allowed from in-memory representation of mount
policy.
Created new constructor for UserIdentity.
Switch the UserIdentity used by RemoteFileStatus.
Renamed TapePoolQueue to ArchiveQueue.
Replaced CreationLog usages with EntryLog.
Renamed TapeQueue to RetrieveQueue.
Removed support for data now gone to catalogue from RootEntry.
Removed corresponding structures from object store.
Removed corresponding calls from SchedulerDatabase and inheriting
classes (OStoreDB).

This allows spawning a subprocess from a process using lots of memory without issue.
Otherwise the kernel will make sure we have in memeory+swap enough to accomodate 2*size of the parent process.

Made the non-implemented functions of Scheduler throw exceptions instead doing and returning nothing.

Fixed minor issues preventing the queueing of requests in SchedulerTest, DISABLED_archive_to_new_file

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.