over: rename ->connect method to ->dbh

over: rename ->connect method to ->dbh

`->connect' is confused with the perlfunc for the `connect(2)'
syscall, and also `DBI->connect'.  Since SQLite doesn't use
sockets, the word "connect" needlessly confuses me.  Give
it a short name to match the field name we use for it, which
also matches the variable name used by the DBI(3pm) and
DBD::SQLite(3pm) manpages.