Done.

Partially implemented.

The Catalogue::getTapePools() method called by the CTA front-end
now returns an std::list of TapePool structures, where each
structure now has the following additional "summary"
member-variables:

  /**
   * The total number of tapes in the pool.
   */
  uint64_t nbTapes;

  /**
   * The total capacity of all the tapes in the pool in gigabytes
   * (10^9 bytes).
   */
  uint64_t capacityGigabytes;

  /**
   * The total amount of compressed data written to all the tapes
   * in the pool in gigabytes * (10^9 bytes).
   */
  uint64_t dataGigabytes;

These three additional member-variables can now be used by the
CTA front-end to provide the summary information requested by
issue #136 in the appropriate format / presentation.  For example,
the CTA front-end could subtract dataGigabytes from
capacityGigabytes in order to calculate the approximate amount of
free space.  Please note that this calculation could potentially
result in a negative number due to the fact that capacityGigabytes
is an approximate number entered by a tape operator for each tape
when they register those tapes into CTA.  In such a case the CTA
front-end should display 0 and not the negative result.

Moved TapePool from common::dataStructures:: to catalogue:: because it belongs to the Catalogue interface

added to the interfaces the features requested by Vlado: label/lastwrite/lastread logs, encryption key and lbp tag for tapes; and encryption flag for pools

The report packer should now also be referenced in the tape recall thread, so it can report the drive status.
testingMocks/MockRetrieveMount.hpp needs to be improved so it handles les end of session correctly.
Then the mechanism has to be mirrored in Archives (simpler case).

Fixed 4 bugs that are preventing DataTransferSessionGooddayRecall test to succeed. One more left: next commit will do

Completed support for tape density and add usage of at() in a vector access to prevent segfault in unit test.
Removed some throw() specifications which led to segfaults.

Simplified redundant code in symetric function for ArchiveMount.

The SchedulerDB provides a TapeMountDecisionInfo object, which contains all that the schduler needs to decide what
tape mount to start. The tape mount decision info then creates an archive or a retrieve mount with 2 separate methods.
The schedulerDB does not have a bare TapeMount class any more. On the scheduler itself will.

The bottom line is the Mount and Job classes shall be passed around the
tapeserverd daemon for two purposes, to carry all the information about
the file copy to be transfered and to provide the notification interface
to the scheduler on which the tapeserverd daemon needs to call methods
to indicate the ends of transfers and mounts.

Improved the readbility of the Scheduler code by replacing dynamic casts with the addition of a simple getMountType() method to the TapeMount, ArchiveMount and RetrieveMount classes

Homogeneize the naming: removed mixtures of archival and archive in favor of the latter. Same the retriv{e,al}.
Renamed file transfers to tape jobs as a single file can required several jobs (in the case of nultiple copies).

Moved all of the classes in middletier/common to the scheduler directory because most of them are specific to the scheduler.  Please feel free to move those that are no so specific elsewhere.

middletier, itself separated in interface, SQLite, objectstore and
shared tests.
Moved all utilities (exceptions, threading...) to a shared utility
directory.
Created a single, shared unit test from all the scattered ones.

License comment is no longer filtered out by doxygen when generating web pages of the individual source files.