Rename KV_RO to Crunch

And add some helper functions to generate crunched files.
Fix lib_test/ after the move from KV_RO to Crunch
Version bump
Add CHANGES entries
Update autogen files
Start playing with module combinators

This is greatly inspired by the design of Ctypes

Does not compile yet -- it's just an experiment, we'll see where it goes
WIP
More WIP
It builds
More WIP

lib_test/console works but not lib_test/kv_ro yet
lib/kv_ro works
Expose a way to create module signature and implementation combinators
Simplify some code
Fix the 'make clean' command
Set the correct debug section after loading a config.ml file
Adapt the remaining tests to the new API
Add some spaces in the generated code
Add a broken combinator test
Update gitignore
Add missing mli file