Setting tag PLCAPI-5.0-1

first working version of 5.0:
pld.c/, db-config.d/ and nodeconfig/ scripts should now sit in the module they belong to
nodefamily is 3-fold with pldistro-fcdistro-arch
site and person tags
new methods GetSliceFamily and GetNodeFlavour
deprecated the dummynet stuff that were for the external dummyboxes
tags definition : more consistency between db-config scripts and accessors
(get accessor to create the tag type too if absent)
logging an event for AddSliceToNodes