Transaction handling by dumping and loading

* The stored procedure for akdump didn't have a transaction. It only worked with Persistit, not FDB.
* Make COPY table FROM honor periodic commit mode.

If magic integer values is too C-like, I can make a separate enum to accompany the count.

Also includes a .gitignore, based on the existing .bzrignore, adjusted for how one specifies a top-level file.