Sql server compact as biggy backing store, rewritten for happy new API

Hi there!

As I promised I adjust SqlCe implementation for new API (and fix some bugs by the way). I tried reuse as much "big" sqlserver code as works with ce edition. 

Difference are:
 * own Insert() because fetching back auto-pk cannot be done in single command,
 * bulkInserts for both store and documentStore, here I need to reuse connection, because of "open sessions limit"

No changes in core Biggy modules.

Please, let me know what do you think, thanks!