Add delete_db_files and delete_all_db_files
Add delete_db_files and delete_all_db_files

Change-Id: I3a6cae154777c42fbddf3ccf0ab673f79da785f1
Reviewed-on: http://review.northscale.com/3122
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Tested-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>

membase/ns_server,pavel-blagodov/ns_server,mschoch/ns_server,nimishzynga/ns_server,pavel-blagodov/ns_server,nimishzynga/ns_server,membase/ns_server,t3rm1n4l/ns_server,membase/ns_server,mschoch/ns_server,membase/ns_server,membase/ns_server,ceejatec/ns_server,nimishzynga/ns_server,mschoch/ns_server,ceejatec/ns_server,ceejatec/ns_server,mschoch/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,mschoch/ns_server,vzasade/ns_server,ceejatec/ns_server,daverigby/ns_server,ceejatec/ns_server,daverigby/ns_server,vzasade/ns_server,vzasade/ns_server,pavel-blagodov/ns_server,daverigby/ns_server,pavel-blagodov/ns_server,t3rm1n4l/ns_server,vzasade/ns_server,daverigby/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,daverigby/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,membase/ns_server,nimishzynga/ns_server,mschoch/ns_server