The DbProvider updated, so now we can define the Database metadata in the quartz configuration section of the application too (which has a precedence over the embedded configuration)

Implementation details:
 - DbMetadataFactory: abstraction for metadata creation/query.
 - EmbeddedAssemblyResourceDbMetadataFactory:  the existing behavior
 - ConfigurationBasedDbMetadataFactory: new configuration based behavior
StdSchedulerFactory validation error fixed
Merge branch 'master' of https://github.com/DrakOOnIC/quartznet
Merge pull request #147 from DrakOOnIC/master

Support for defining DbMetadata via configuration (in the quartz section)