Fixed process manager going to polling after timeout handler requested shutdown/kill/fork instead of handling the request.
Gathered the handlers for unit tests in a different file.

The CMakeLists.txt file of the catalogue directory instructs
cmake to generate SqliteCatalogueSchema.cpp, by combining
the contents of the SqliteCatalogueSchema.before_SQL.cpp with the
contents of catalogue_schema.sql.  This means the
SqliteCatalogueSchema.before_SQL.cpp file is not compilable.

The purpose of the SqliteCatalogueSchema structure class is to
isolate the "non-compilable" issues into a small and encapsulated
compilation unit, namely SqliteCatalogueSchema.o, so that the
remaining business logic can be implemented in the non-generated
and compilable SqliteCatalogue.cpp file.  This means that IDEs can
work as normal with SqliteCatalogue.cpp, whereas they will struggle
with SqliteCatalogueSchema.before_SQL.cpp which is therefore
intentionally small.

The SqliteCatalogue.cpp file is now generated by cmake from combining
the SqliteCatalogue.cpp_before_SQL_schema and catalogue_schema.sql
files.

Renamed the instance field of the ArchiveFile into diskInstance\nAdded a comment for the lastUpdateTime field of ArchiveFile\nWord wrapped comments of the data structures

Added comments in the EOS interface doc.\nRenamed MountGroup into MountPolicy and removed MountPolicy (adapted SQL code).\nRemoved amount of data to warrant a mount from LogicalLibrary.

Added last update time in the ArchiveFile and split the updatefileinfo command in two: updatefileinfo (run by EOS during resynchronization process) and updatefilestorageclass (run by EOS on behalf of a user who wants to change the storage class of a file)

Changed the documentation fro the eos interface and the instance crosstalk, renamed User into Requester, refactored all the SQLITE code to have a GROUPNAME column in the requester, changed the tests

Re-enabled the helgrind tests that triggered it.

relies on global variables managing files which were deleted on child process exit.
Helgrind is currently disabled for the multiprocess unit test as it makes it fail.

Added silencing of valgrind information for child processes.
Added protocol buffers cleanup at the end of unit tests.

Added ProcessManager class which owns the main loop.
Fixed a bug when closing the wrong side of the socketpair in SocketPair.
Minor fixes to tape daemon code.

Changed the interface to EOS doc and changed the type of the first parameter of catalogue.getArchiveFiles from uint64_t to string