ui: Improved user experience of error display

* label errors as errors instead of references in file snippet headers
* show number of fatal errors in file snippet headers as well
* only show the first 10 error snippets open, remaining collapsed
* don't show status message after parsing in red on errors
* don't show stats of parsing when project was only loaded

src/lib/data/ErrorInfo.h

@@ -0,0 +1,29 @@
+#ifndef ERROR_INFO_H
+#define ERROR_INFO_H
+
+#include "utility/file/FilePath.h"
+#include "utility/types.h"
+
+struct ErrorInfo
+{
+	ErrorInfo()
+		: id(0)
+		, isFatal(false)
+	{
+	}
+
+	ErrorInfo(const std::string& message, const FilePath& filePath, Id id, bool isFatal)
+		: message(message)
+		, filePath(filePath)
+		, id(id)
+		, isFatal(isFatal)
+	{
+	}
+
+	std::string message;
+	FilePath filePath;
+	Id id;
+	bool isFatal;
+};
+
+#endif // ERROR_INFO_H