rdkit/rdkit: 2017_09_3 (Q3 2017) Release

Release_2017.09.3 (Changes relative to Release_2017.09.2) Acknowledgements: Jason Biggs, Brian Kelley, Noel O'Boyle, Paolo Tosco Bug Fixes: Missed symmetrization in R-Group decomposition (github issue #1659 from bp-kelley) Acetylenic hydrogens not given appropriate 2D coordinates (github issue #1691 from jasondbiggs) Warning on import of rgroup decomposition package (github issue #1695 from greglandrum) AUTOCORR2D.h not installed unless RDK_BUILD_DESCRIPTORS3D but is required (github issue #1702 from baoilleach) Dative bonds interfere with kekulization and the perception of aromaticity (github issue #1703 from greglandrum) bonds that are STEREOCIS or STEREOTRANS cannot be depickled (github issue #1710 from greglandrum) Added dependency from Boost headers to PgSQL CMakeLists.txt (github pull #1717 from ptosco