Split out glew settings to separate .pri file

git-svn-id: http://svn.clifford.at/openscad/trunk@530 b57f626f-c46c-0410-a088-ec61d464b74c

glew.pri

@@ -0,0 +1,19 @@
+glew {
+  !deploy {
+    # Optionally specify location of GLEW using the 
+    # GLEWDIR env. variable
+    GLEW_DIR = $$(GLEWDIR)
+    isEmpty(GLEW_DIR) {
+      # Default to MacPorts on Mac OS X
+      macx: GLEW_DIR = /opt/local
+    }
+    !isEmpty(GLEW_DIR) {
+      INCLUDEPATH += $$GLEW_DIR/include
+      LIBS += -L$$GLEW_DIR/lib
+      message("GLEW location: $$GLEW_DIR")
+    }
+  }
+
+  unix:LIBS += -lGLEW
+  win32:LIBS += -lglew32
+}