Fixed wrong shutdown status reporting in signal handler (it is always ready to shutdown).

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.