D bindings for Shapefile C Library

[Craig Dillabaugh]

I've created bindings for the C Shapefile Library.  Shapefiles
are a format used commonly in vector based Geographic Information
Systems, often for data interchange. It is a pretty simple
library and it is my first effort at creating such bindings.

https://github.com/craig-dillabaugh/shplib.d

I've looked in Demios and code.dlang.org to see what the standard
setup for such bindings is, and while most are similar there
doesn't seem to be an accepted layout.  If anyone has a moment to
spare I would be happy if someone could have a look to see if
there are any obvious improvements that should be made.

I plan to run a few more tests on my bindings, and once those all
work, I hope to add this to code.dlang.org.