Add GenerateSourceGroups macro.
Attempt to generate source_group for IDEs reflecting folders structure.
No functional changes to build configuration included.

git-svn-id: http://svn.osgeo.org/geos/trunk@4036 5242fede-7e19-0410-aef8-94bd7d2200fb
Fix MSVC handling of strtod (Thanks to Paul Kohut for the patch submitted as part of https://github.com/libgeos/libgeos/pull/31/)
Apparently, it solves the long running INF/NAN parsing issues on Windows and enables GEOSisValidDetail test pass again.
It should also solve problems reported as part of ticket #509.

git-svn-id: http://svn.osgeo.org/geos/trunk@4037 5242fede-7e19-0410-aef8-94bd7d2200fb