Merge branch 'master' into v0.6.0

# Conflicts:
#	src/ifcconvert/IfcConvert.cpp
#	src/ifcgeom/IfcGeomFilter.h
#	src/ifcgeom/IfcGeomIteratorImplementation.h
#	src/ifcgeom/IfcGeomWires.cpp
#	src/ifcparse/IfcFile.h
#	src/ifcparse/IfcLogger.cpp
#	src/ifcparse/IfcLogger.h
#	src/ifcparse/IfcParse.cpp
#	src/serializers/SvgSerializer.cpp
#	src/serializers/schema_dependent/XmlSerializer.cpp

src/ifcparse/IfcLogger.h

@@ -36,12 +36,13 @@
 class IFC_PARSE_API Logger {
 public:
 	typedef enum { LOG_NOTICE, LOG_WARNING, LOG_ERROR } Severity;
+	typedef enum { FMT_PLAIN, FMT_JSON } Format;
 private:
 	static std::ostream* log1;
 	static std::ostream* log2;
 	static std::stringstream log_stream;
 	static Severity verbosity;
-	static const char* severity_strings[];
+	static Format format;
 	static boost::optional<IfcUtil::IfcBaseClass*> current_product;
 public:
 
@@ -51,9 +52,14 @@ public:
 
 	/// Determines to what stream respectively progress and errors are logged
 	static void SetOutput(std::ostream* l1, std::ostream* l2);
+
 	/// Determines the types of log messages to get logged
 	static void Verbosity(Severity v);
 	static Severity Verbosity();
+
+	/// Determines output format: plain text or sequence of JSON objects
+	static void OutputFormat(Format f);
+	static Format OutputFormat();
 	
 	/// Log a message to the output stream
 	static void Message(Severity type, const std::string& message, const IfcUtil::IfcBaseClass* instance = 0);