added basic scaffolding for db import feature (button, server returns list of tables in 'customer_db_1')
the 3 screens of the 'import schema' wizard are complete, next must hook up to the table renderer
stub code on server now creating sample database (customer_db_1) with full schema and sample data, for testing schema importing
added default_auto_layout_spacing_horizontal setting to tableManager, which takes effect when importing external db schema and the UI decides where to initially put all the tables; fixed minor bugs with ui jumping when certain links were clicked
schema importer improvements
db schema import feature: created SchemaImporter class and moved related methods there (getSchema, getTableFields(), getRelationships())
more work refactoring SchemaImporter
schema importer is now importing foreign key relationships, in the format the UI needs to render them
removed all warnings except serialVersionUID
database importer UI now draws the introspected foreign-key relationships on the screen
fixed bug where importing schemas with no relationships would cause import to fail
fixed bug that prevented deletion of tables
table renderers now auto-adjust their width to match their contents
failed attempt to fix layout issues caused by adding field type and foreign-key markers
primary key fields now show (PK) after field name
simplified code to tell UI which fields are primary keys
fixed bug in showing datatype/PK after field name in db editor
fixed bug where reordering fields would cause foreign-key lines to jump to the wrong location
merged db_schema_import branch into master