This is necessary because commit 8131a24 (Tue Mar 27 10:08:13 2012) started passing the config section name rather than hardcoding "AssetService"
This meant that the HG external-facing asset service tried to read ConnectionString from [HGAssetService] rather than [AssetService].
On SQLite, not finding this meant that it fell back to [DatabaseService], which is set for OpenSim.db rather than Asset.db.
Therefore, all external asset requests returned null.
Solution taken here is to create an [HGAssetService] section with the same ConnectionString as [AssetService].
This bug does not affect normal MySQL/MSSQL config since they use the [DatabaseService] connection string anyway.
Addresses http://opensimulator.org/mantis/view.php?id=6200, many thanks to DanBanner for identifying the exact problem commit which was very helpful.
This was a regression from OpenSimulator 0.7.3.1 which did not contain this bug.
Update information in StandaloneCommon.ini.example to reflect this
Remove ISharedRegionModule interfaces from all SimianGrid connector classes temporarily since this stopped standalone from working (due to absence of AssetURI settings, etc.).
Solution here may be to create separate region module connectors as done by local/grid/hypergrid so that loading can be controlled via include files
Or otherwise work out how to stop these modules from being loaded for all OpenSim invocations