Log Message:
Update to 1.18

Version 1.18 August 2016

* configure.ac : patch by Greg Troxel <gdt@lexort.com>
     CPPFLAGS was set with +=, which is a bash extension and fails on
     POSIX-conforming shells.  This resulted in sqlite3 support not being
     enabled on NetBSD, even though the sqlite3 library was found and
     linked in.
* fixed some minor problems reported by Greg Troxel (doc, NEWS)
* in local/network.cpp commented out // removed_obs.clear();
* fixed a formatting bug in outlaying terms (due to c++11)
* fixed a bug in HTML parser test
* simplified class LocalPoint
* fixed a bug in sql export reported by Dominik Hladik
* added @documentencoding UTF-8 into gama.texi