#2 Polygon layer compile errors with MSVC

[Robert Quattlebaum]

The polygon layer implementation that was included
with version 0.01.00 does not compile with the Visual
C++ 6.0 compiler, thus breaking the build.

[Robert Quattlebaum]

Logged In: YES
user_id=206661

For v0.01.01, the polygon layer has been disabled for MSVC
builds. I hope to resolve this issue soon, but I am running
low on patience regarding Microsoft tools.

But at least it now compiles and runs.