Fix import commands incorrectly shutting down the graph.

The command entry point launcher, which initialises the graph in the
first place, is responsible for doing this.
Improve scripting docs
Add proper transaction handling on csv import manager
Flesh out builddb script (inc. dodgy hard-coded paths to data)
Fix formatting of ruby code to use 2-space indent
Typo fix
Tidy-ups and commenting
Merge branch 'master' into tp-2.4.0-sparql