Define qsar descriptor implementations for service provider interface (SPI).

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Ensuring all bond descriptor extend the abstract superclass.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Ensuring all atom descriptor extend the abstract superclass.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Introducing new abstract super class to allow default implementations - mirrors the preexisting abstract classes for atom/bond descriptors.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Ensure atom pair descriptors extend the abstract super class.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Adding abstract super class to all molecular descriptors.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Adding descriptor initialisation for those which require it.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Using service provider interface (SPI) to load tsar descriptors. This simplifies the loading process, doesn't depend on jar locations and removes the magic constants (int parameters) being used to decide which descriptors to load.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>
Removing descriptors which can not be run by DesriptorEngineTest. These descriptors are in qsarionpot and qsarprotein, as the DesriptorEngineTest is in qsarmolecular they can not be loaded. Additional SPI files can be added to those modules (not in the current build system), or perhaps their classes should be merged into the other qsar modules.

Signed-off-by: Egon Willighagen <egonw@users.sourceforge.net>