Several changes to make Mingw happy

src/OpenMesh/Core/CMakeLists.txt

@@ -35,7 +35,7 @@ if ( NOT ${PROJECT_NAME} MATCHES "OpenMesh")
 endif()
 
 
-if (WIN32)
+if (WIN32 AND NOT MINGW)
 
   if ( OPENMESH_BUILD_SHARED )
     add_definitions( -DOPENMESHDLL -DBUILDOPENMESHDLL)

src/OpenMesh/Tools/CMakeLists.txt

@@ -25,9 +25,9 @@ acg_append_files (sources "*.cc" ${directories})
 #Drop the template only cc files
 acg_drop_templates(sources)
 
-IF(WIN32)
+IF(WIN32 AND NOT MINGW)
   acg_append_files (sources "*.c" ${directories})
-ENDIF(WIN32)
+ENDIF(WIN32 AND NOT MINGW)
 
 # Disable Library installation when not building OpenMesh on its own but as part of another project!
 if ( NOT ${PROJECT_NAME} MATCHES "OpenMesh")