This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
Improves the generic database used by some import scripts:
* Adds additional columns for users
* Adds support for attachments
* Allows setting the data type for keys (numeric or string) to ensure correct sorting
Loïc Guitaut
David Taylor
Gerhard Schlager
Sam Saffron