Full-text searching with SQLite #152

While the FTS5 extension for SQLite is not included in the standard PHP distribution (and loading the extension at run-time is practically impossible), recent Debian does include FTS5 in its libsqlite3-0 package, which PHP uses.

Given the above, The Arsse would need to detect the presence of FTS5 at start-up, check whether relevant full-text virtual tables exist if so, and create them if they do not exist.