update to geos 3.7.1 binaries, support more plaforms

[visr]

Note that there are several new functions added to the C API according to
https://trac.osgeo.org/geos/browser/git/NEWS?rev=3.7.0
These are not wrapped as part of this PR, but can be added separately.

[visr]

Something is wrong on windows 64 bit, I also see it locally. No idea what though.

[visr]

Loading LibGEOS works fine, but the first time it fails is on reading WKT strings: using LibGEOS; readgeom("POLYGON((0 0,1 0,1 1,0 0))")

Or lowered manually to a ccall:

using LibGEOS
c = LibGEOS._context
r = LibGEOS.WKTReader(c)
w = "POLYGON((0 0,1 0,1 1,0 0))"
ccall((:GEOSWKTReader_read_r,LibGEOS.libgeos),Ptr{LibGEOS.GEOSGeometry},(LibGEOS.GEOSContextHandle_t,Ptr{LibGEOS.GEOSWKTReader},Cstring),c.ptr, r.ptr, w)

It just goes poof and closes julia without saying anything. If anyone has any ideas, or how to debug, I'd be all ears :)

Don't see how this should only affect Windows 64 bit, unless the build is bad somehow.

[visr]

Ok, updating to 3.7.1 which just came out fixes the old Win64 issue. Locally it works well on Win64, don't understand the error on AppVeyor though

Edit: scrap that, locally I see the same now, must have tested something else.