Make prefs a module variable and save a link to vertexcache in Clutter to avoid having to pass both in whenever we want to doing anything with a Clutter object.
Fix for elevation of objects on tile borders.
Lines have a default TEX_WIDTH of 1.
Minor tidy.
Fix for loss of placement precision on reading DSF.
Detect v10.21 (which has support for tile-straddling Facades) and later.
Release 2.44.