Define dynamically the methods enabled by flags in BiodbConn

[pkrog]

In BiodbConn some methods form groups belonging to features that are enabled by flag inside definitions.yml.
Examples are : downloadable, remote, writable, compound.db, etc.
Would it be possible to move these methods by group in specific class or source file, and define them dynamically inside the concrete class at the moment it is instantiated.
This would decrease the number of methods defined inside BiodbConn, and allow to extend biodb by easily adding more of these features.
When defining those methods dynamically, a check could be made also on implementation of abstract methods (do... methods most of the time) inside the concrete connector class.