Add support for SQLite dictionaries

Add support for SQLite dictionaries

The krb5-strength plugin and heimdal-strength program now support a
SQLite password dictionary.  This format of dictionary can detect any
password within edit distance one of a dictionary word, meaning that
the dictionary word can be formed by adding, removing, or changing a
single character in the password.  A SQLite password dictionary can be
used alone or in combination with any of the other supported
dictionary types.  SQLite dictionary support is based on work by David
Mazières.