CONFIG -= plugin if shared_app.pri links to it.

Index: src/core/core.pro
--- src/core/core.pro.orig
+++ src/core/core.pro
@@ -307,7 +307,7 @@ r_static_libs {
     CONFIG += staticlib
 }
 else {
-    CONFIG += plugin
+    #CONFIG += plugin
 }
 
 QT += concurrent
@@ -319,7 +319,7 @@ RC_FILE = core.rc
 OTHER_FILES += core.dox math/math.dox
 DEFINES += QCADCORE_LIBRARY
 
-LIBS += -lopennurbs -lzlib
+LIBS += -lopennurbs -lz
 
 win32 {
     LIBS += -lRpcrt4 -lAdvapi32
