This removes the dependency on django from docload, facilitating
incremental upgrades of the infrastructure.
This now requires a new docload.ini file in the tools/docs directory,
with a section "db" and a setting "dsn".
This makes it possible to figure out when the docs were actually
loaded, since developer docs don't carry a version number. This is
actually going to be the docs *load* timestamp, and not build timestamp,
but they should be close enough together that it shouldn't matter.
Fixes#108
