Merge pull request #405 from rmansoor/5.1-LEGACY

[PDI-10871] - Creating an interface and a default implementation for the staging database
[BISERVER-11217] Update the metadata datasource to store an Instaview datasource type property - Adding flag to instaview generated metadata data sources. Added xmi extension to metadata datasource in export manifest. Also added generic WIZARD_GENERATED_DATASOURCE to avoid having to explicitly omit each generated metadata data source type. Added instaview datasource service and javascript for custom datasource type
Merge pull request #406 from pminutillo/5.1-LEGACY

[BISERVER-11217] Update the metadata datasource to store an Instaview da...
[BISERVER-11217] - Added creatable flag, omit datasource types from create new list with creatable flag = false
Merge pull request #407 from pminutillo/5.1-LEGACY

[BISERVER-11217] - Added creatable flag, omit datasource types from crea...
[PDI-10781] - Create/update agile mart datasource from properties files