No need for model package, no more name clashes
Prefer EXCISE to ERASE for what should be DELETE
Ensure no interface function clashes with CL symbol

Of course there is no single right way but this makes the example
code as simple as possible which is a virtue in itself.
Only need for one simple example

No more package qualification.
Rename simple-2 example just simple
Tidy up examples given new model interface names
Cleanup user guide
Add ENSURE-MODEL and ENSURE-BACKEND to interface
fixup README and TODO
fixup beginners doc
fixup user-guide
fixup get -> fetch rename
fixup get->fetch rename
Tidy up package exports
Remove ! from drop-model and drop-backend
fixup DELETE -> EXCISE
fixup ensure-backend
fixup user-guide
Move user query doco to user guide
fixup previous