Modify NAnt target in Prebuild to copy .mdb files to bin in debug configuration. (bug #55)

Use 'mono --debug OpenSim.exe' to get line number output on stack traces.

Prebuild/src/Core/Targets/NAntTarget.cs

@@ -379,6 +379,9 @@ namespace Prebuild.Core.Targets
                         ss.WriteLine("            <fileset basedir=\"${project::get-base-directory()}/${build.dir}/\" >");
                         ss.WriteLine("                <include name=\"*.dll\"/>");
                         ss.WriteLine("                <include name=\"*.exe\"/>");
+                        ss.WriteLine("                <if test=\"${build.debug=='true'}\">");
+                        ss.WriteLine("                  <include name=\"*.mdb\"/>");
+                        ss.WriteLine("                </if>");
                         ss.WriteLine("            </fileset>");
                         ss.WriteLine("        </copy>");
                         break;