r12194: Ensure that when we set a connection path we've canonicalized

r12194: Ensure that when we set a connection path we've canonicalized
the name (must be abolute - start with /, must not end in /,
must have ./ and ../ removed). Of course for realpath resolved
paths this won't be the case but for others we need this name
to be canonicalized. This name is going into the sharemode db
for #3303 so needs to be in a normalized format.
Jeremy.
(This used to be commit 22e3300911809692b595f49e87d91e3111923e6a)