The deletion of the mock name server path in the destructor occurs only if the object was created using the empty constructor (this is what happens in unit tests)

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

Also organised common in subdirectories, and added sub directory for mockDB.

the uid and gid of the CTA user that owns the file.

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.

Ported the directory creation of Vfs to MockNameServer, so the unit tests can pass in the presence of leftover temporary files.

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.