Moved some parts to a static lib so both the executable and the tests can link to it.

Written additional tests.

core/CsvWriter.h

@@ -0,0 +1,23 @@
+#ifndef CSVWRITER_H
+#define CSVWRITER_H
+
+#include <ostream>
+#include <QTextStream>
+
+class CsvWriter {
+public:
+	CsvWriter();
+	explicit CsvWriter(QTextStream *output);
+	void setDestination(QTextStream *output);
+	void setSeperator(QChar ch);
+	void setQuote(QChar ch);
+	void writeField(QString field);
+	void nextRow();
+private:
+	QChar m_seperator = ',';
+	QChar m_quote = '"';
+	QTextStream *m_output = nullptr;
+	int m_column = 0;
+};
+
+#endif // CSVWRITER_H