Fix COLLADA build error. This was caused by the difference in OpenCollada versions between Windows and Linux/Mac. Windows uses OpenCollada revision 746, Linux/Mac - 721.

source/blender/collada/DocumentExporter.cpp

@@ -1719,7 +1719,11 @@ public:
 				// most widespread de-facto standard.
 				texture.setProfileName("FCOLLADA");
 				texture.setChildElementName("bump");				
+#ifdef WIN32	// currently, Windows builds are using revision 746 of OpenCollada while Linux and Mac are using an older revision 721
 				ep.addExtraTechniqueColorOrTexture(COLLADASW::ColorOrTexture(texture));
+#else
+				ep.setExtraTechniqueColorOrTexture(COLLADASW::ColorOrTexture(texture));
+#endif
 			}
 		}
 		// performs the actual writing