over it with vdef.h.

Confine __unused to include/vtree.h at the same time.

reveal to vapi/vsm.h for it to work, and the truly private parts
needed to implement things internally (vsm_priv.h)

This is necessary for VMODs which implement secondary hash-keys.

Patches from martin@ with some minor tweaking by me.

failing that, try to get better diagnostics about what it does wrong...

Fixes #1688

The backend matching function now uses shell-like glob'ing:

	backend.list *	-> all backends in active vcl
	backend.list *.* -> all backends in all vcls
	backend.list *.foo -> all backends named 'foo' in all vcls
	backend.list bar.* -> all backends in the vcl named bar

now.

Rename VBE_Drop() to VBE_DeleteBackend()

into which pointers are returned.

This simplifies the code enough that FlexeLint doesn't get confused.

unique objects for each VCL which instantiate them.  (Instead we
share TCP connection pools, which are a lot simpler)

Spotted one utterly trivial memory leak along the way.

about, and return NULL if they won't tell us.