Merge pull request #1 from fabuzaid21/master

Initial implementation of Shares algorithm
- Merging Shares and DYS under a single interface that extends JoinsAlgorithm.
- Merges SharesArguments and DYSArguments under JoinsArguments.
- Adds YannakakisShares (but not yet implemented).
removing shares directory.
- Adding an empty SortedNestedLoopJoinShares.scala.
- Making kyro a command line option.