ccan: we're subsystems, not a library.

ccan: we're subsystems, not a library.

Don't expose a libccan.so; it would produce clashes if someone else
does the same thing.  Unfortunately, if we just change it from a
SAMBA_LIBRARY to a SAMBA_SUBSYSTEM, it doesn't create a static library
as we'd like, but links all the object files in.  This means we get
many duplicates (eg. everyone gets a copy of tally, even though only
ntdb wants it).

So, the solution is twofold:
1) Make the ccan modules separate.
2) Make the ccan modules SAMBA_SUBSYSTEMs not SAMBA_LIBRARYs so we don't
   build shared libraries which we can't share.
3) Make the places which uses ccan explicit.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Autobuild-User(master): Rusty Russell <rusty@rustcorp.com.au>
Autobuild-Date(master): Fri Jun 29 06:22:44 CEST 2012 on sn-devel-104