Merge tag 'rdf-trine-1.009'

RDF::Trine 1.009.
Some basic failing tests
Random order triple patterns test
find the variable graph
first stab at sorting subpatterns
sum the unicode code points for a final sort criterion
record the triple patterns involved
create a list of list with the patterns that are to be sorted
some logging
edges are not used
trivial change
Implement a sort based on assigning numbers to the different triple
patterns in the HSP paper, thus implementing Heuristic 1 and 4
Some documentation
Special case when the block has 0 or 1 patterns left
Fix bug in pushing patterns
remove debug dumping
remove commented-out code
Fixed missing =cut POD syntax.
Fix some tests
comment the code a bit
more tests
add deterministic sorting sum