downgradePrivDesc in PrivDesc
get rid of unLIOTCB.  Selctors make me nervous on TCB types.
clean up some privilege comments
check in alternate, faster DC label type; candidate to replace DCLabels
export list
document the new DCLabel.hs;
move the old stuff to Old and remove it from the .cabal file
(it's still used by examples/dcbench.hs)
be consistent about safe imports and make more Typeable instances
deprecate some confusing functions
DCLabeled
comment DCLabel
Read instance for DCLabel
dcPub, dcTop, dcBottom, instance ToCNF DCPriv
Merge branch 'master' of github.com:scslab/lio

Conflicts:
	lio/LIO/DCLabel.hs
dcPub -> dcPublic
doc improvements
more safe imports
goodbye Privs, hello Delegate
get rid of ...PrivDesc suffix and just use ...P.
first cut an new error facility
better error reporting in LMVar