fix documentation typo
adds find_or_create_by to ActiveNode

Also adds the bang version `find_or_create_by!`

Both methods are equal to the ones defined in ActiveRecord::Relation.
Merge pull request #535 from mrfoto/find_or_create_by

Adds find_or_create_by
adds a block to :create and some specs
Merge pull request #536 from neo4jrb/create_specs

adds a block to :create and some specs
Fix URL
Fix URL

(cherry picked from commit 2130e0263c29f22a9259219d8addd493d76b217b)
Merge branch 'master' of github.com:neo4jrb/neo4j
count uses pluck, retrains ID of target var
Merge pull request #538 from neo4jrb/count_retains_target

count uses pluck, retrains ID of target var
allows ordering of paginated results
Merge pull request #539 from neo4jrb/pagination_fix

allows ordering of paginated results
adds new activerel query method
Merge branch 'master' into metadata
Put this back.  Turns out it's not neccessary
Undo ActiveRel stuff which is now in separate branch
Should now be able to get along without _classname