Remove duplicated plPickNode code

This fixes some of the "multiple definition of symbol" warnings we get
from the linker. I checked this against the OU AllDlls solution and
deleted the version not present in it.
The exporter is a single DLL.

So we don't need to __declspec(dllimport) ANYTHING. This stops more linker
warnings.
Toss useless redefinition.
Merge pull request #377 from Hoikas/max-symbols

Fix Max Plugin Linker Warnings