refactor move overridden methods of wlbud in bud/bud.rb
add current_eval_rule_id attribute to push_elems
minor
full introspection of pushelement in bud structure when shredding rules
bug in path PushStaetfullElement
proper overriding of pushelement constructor
refactor to prevent clash in path because of budoverride + add flag for provenance
Merge branch 'bug_in_path' into push_out

Conflicts:
	lib/bud/budoverride.rb
	lib/bud/collection.rb
Revert "Merge branch 'bug_in_path' into push_out"

This reverts commit 4b0dcf56c122eeec465df9603e9a596383168909, reversing
changes made to 10d5333e3097eb17a09a2433a309a8ed8d53cb3d.
add clean string sanitizer for test in provenance
new ProofTree built while push_out elements
optmization with object reference in provenance DONE
extract last psu_elems in rules evaluation to index relations in provenance graph
update ruby engine to 2.1.0 version
add test about pushshjoins duplication
add the deletion alternative
add relation source in order in provenance tracking to disambiguiate self-joins
add reverse index from facts to proof tree + fix case when push_sorted_elems is not sorted because of additionnal scanners + solve multiple output case of scanner elements
minor
test provenance with seeds OK