Fix table name generation, column reading; start FK generation.
Fix table name generation, column reading; start FK generation.

When used against SQLite, most of the columns were missing because
SchemaLoader was GetFullDbName(table, schema), where if schema was null
then table is returned.  However, DbSchemaLoader.ReadTables() wasn't inserting
null as the schema, but "" instead.  The result was e.g. '.Employees' from
GetFullDbName(), which prevent the table from being found within
SchemaLoader.LoadColumns().

Column reading was also screwy because we weren't setting
DataTableColumn.FullType, resulting in ColumnAttribute.DbType being empty in
the generated source.

Finally, found that this is a partially doomed effort: SQL Server doesn't
appear to make foreign-key information available from the DataTable, so
currently foreign-key generation is restricted to the SQLite provider (which
does provide useful information from the DataTable).


git-svn-id: 1800f71f313d917366f95485fa960eed04b40598@1281 33146b6e-df29-0410-a1ca-39be37fb9416

Sectoid/dblinq,Sectoid/dblinq,sharique/dbinq,sharique/dbinq