Update VS2012 project for recent changes
Fix incorrect syntax coming over from merge
MSVC can't handle as many "if/else if" clauses in a single scope as are now in mapgen.cpp. This hack breaks the clause in two so MSVC compiles work, until this file is refactored. Not re-indenting anything as that's likely to cause more headaches for everyone.
Visual Studio users rejoice! Accept PR #4430.