pgr_binaryBreadthFirstSearch GSOC-2019 week 5

[vicennial]

• Added SQL files that contain the function signature for One-to-One, One-to-Many, Many-to-One, Many-to-Many type queries as well as the signature for the internal version of the function.
• Added function C file which accepts the data from Postgres, sets up input/output arrays, calls a function to begin the algorithm, extracts the results and returns it.
• Added function C++ driver file. This file contains the algorithm to process the input data. In the current state, the function will simply return an empty set without processing any of the input data.
• Added InnerQuery pgTap test.
• Added Documentation queries and their (dummy)results. The results would be updated later once the actual algorithm has been implemented.
• Added the function signatures to pgrouting--3.0.0.sig .