moving the basic stuctural queries to constructs
refactoring the graph queries to be in a seperate namespace
typos, dead code removal and minor refactorings
bug fix at graph
refactorings of the graph module
adding subsetting to incoming and outgoing refs
refactoring timestamped to be called layer
refactoring storage to use protocol and record
Merge pull request #71 from yoavrubin/master

Updates and fixes found during chapter writing time