ui: revised project setup wizard

* adjusted some help texts
* moved exclude paths and source file extensions contents to indexed paths selection in project setup wizard
* removed compiler flags from CDB project setup wizard
* added wizard content that shows some info text regarding the purpose of source groups
* renamed ContentSummary to ContentGroup
* fixed issue with CompilationDatabase include path extraction

src/lib_gui/qt/window/project_wizzard/QtProjectWizzardContentSourceGroupInfoText.cpp

@@ -0,0 +1,35 @@
+#include "qt/window/project_wizzard/QtProjectWizzardContentSourceGroupInfoText.h"
+
+QtProjectWizzardContentSourceGroupInfoText::QtProjectWizzardContentSourceGroupInfoText(QtProjectWizzardWindow* window)
+	: QtProjectWizzardContent(window)
+{
+}
+
+void QtProjectWizzardContentSourceGroupInfoText::populate(QGridLayout* layout, int& row)
+{
+	QHBoxLayout* layoutHorz = new QHBoxLayout();
+	layout->addLayout(
+		layoutHorz, 
+		row, QtProjectWizzardWindow::FRONT_COL, 
+		1, 1 + QtProjectWizzardWindow::BACK_COL - QtProjectWizzardWindow::FRONT_COL, 
+		Qt::AlignTop
+	);
+
+	layoutHorz->addSpacing(60);
+
+	QLabel* infoLabel = new QLabel(
+		"<p>Please add at least one source group to your project. A source group specifies which source files should be "
+		"analyzed by Sourcetrail and includes all parameters required to analyze those source files. A Sourcetrail project "
+		"may contain multiple source groups, which may be necessary if you want to analyze source files from different "
+		"projects that do not share the same parameters.</p>"
+		"<p><b>Hint</b>: If your project contains source code for multiple build targets, you can add all of those source "
+		"files with one single source group as long as they all share the same parameters.</p>"
+	);
+	infoLabel->setObjectName("info");
+	infoLabel->setWordWrap(true);
+	layoutHorz->addWidget(infoLabel);
+
+	layoutHorz->addSpacing(40);
+
+	row++;
+}