minor fix in test and comments
add test for halt scratch
fix kill in test to not kill test suite and other instances
add flag rule :dies_at_tick to stop peers at a given tick and propagate stop message via peer_done
Renamed extended collection name from _ext to _plus to avoid confusion with extentional collections.
Set permissions for KNOWN policy. Due to left-to-right rule evaluation followers need to know all other followers that share an aggregator, and all aggregators need to know each other and be known to all followers.
fix test push_out sort collection
refactor init comments + fix bug in arity in wlvocabulary (relation of arity wero) + fix race condition in file writing
remove oldies
minor modif + add test for differencial sending
prepare differential computation, now still naive sending with new facts
require to fix bad arrray nesting in deep_diff_split_lookup
differential tools are implemented and tested properly
test empty value and filter type shoudl be hash only in deep diff
fix nill value in packets when no facts has to be added or deleted, now it passes an empty hash
fix empty packets problem, now there are filtered before building the content of the channel
fix the runaway problem and insert test to check
Merge remote-tracking branch 'upstream/master'

Conflicts:
	bin/xp/run_xp.rb
	lib/budoverride/bud.rb
	lib/wlbud.rb
	test/ts_webdamlog.rb
Refactored code to separate Emilien's original webdamlog code and access extensions for easier merges in the future.
General cleanup. Removed deprecated run_access_remote script, renamed the main experiment script, made corresponding changes in the python code. Also added the bud patch for tcp sending until bud is released with it.